[{"content":"Another installment in the annals of the bullying of the Shockley surface state, this time the trick isn’t exotic adatoms or massive molecular weight, just a 120° tilt of hexaazatriphenylene (HAT) ligands that converts an achiral lattice into a pair of enantiomeric 2-D metal–organic frameworks. The result: chirality-imposed scattering potentials that lift degeneracies and open ΔE ≈ 80 meV gaps in the Ag(111) two-dimensional electron gas while leaving the global periodicity intact.\nKey take-aways Structural chirality prints straight onto k-space\nnc-AFM resolves two co-existing enantiomers, pinwheel (PW) and “Y” phases, built from Cu–N coordination and an approximately 6° molecular cant relative to the substrate plane. STS maps acquired at 5K reveal the surface-state band dispersion reconstructed by these potentials: back-folded bands, avoided crossings and a pronounced energy gap at the new Brillouin-zone boundary.\nNo new chemistry, only symmetry\nThe gaps appear without changing the molecular building blocks; tilting the HAT plane breaks mirror symmetry and generates the required chiral scattering.\nTwo tools, one story\nElectronic plane-wave expansion (EPWE) calculations feed the experimental topographies into a scattering potential and reproduce the experimental dI/dV linecuts almost quantitatively. DFT overlays the intrinsic MOF bands, showing that substrate hybridisation broadens the pyrazine and shallow-pore states but leaves the chirality-imposed gap untouched. Why it matters Tuning interface electronic properties usually means adding heavy metals, strain or strong correlations. Here the knob is symmetry engineering at the level of a single torsion angle, giving a gap that survives room-temperature disorder and is addressable by STM patterning. For anyone chasing chiral superconductivity, topological Bloch modes or valley-splitting without magnetic fields, that’s a tantalising new dial to turn, keeping in mind that the circumstances of its rotation are a bit rarefied, and the organics that underpin it aren\u0026#8217;t typically associated the materials systems that carry those clusters of keywords.\nAcknowledgments The project has long roots: Sebastian synthesised the first and final HAT batch in-house back in 2019, but that\u0026#8217;s a lot of molecules when you image them by the hundred. The low-temperature data were collected during Julian’s PhD tenure, during the LHe heyday when the coarse motor piezos had been beated back into shape (thanks Ben). Bernard, now a postdoc at LBNL, nevertheless kept pushing the modelling forward to get this across the finish line.\nTuning Interface Electronic Properties via Chiral Two-Dimensional Metal-Organic Frameworks (2025). Small Structures. https://doi.org/10.1002/sstr.202500422\n","permalink":"https://jhell.imipolex.biz/2025/10/20/chirality-in-2d-metal-organic-framework/","summary":"\u003cp\u003eAnother installment in the annals of the bullying of the Shockley surface state, this time the trick isn’t exotic adatoms or massive molecular weight, just a 120° tilt of hexaazatriphenylene (HAT) ligands that converts an achiral lattice into a pair of enantiomeric 2-D metal–organic frameworks. The result: \u003cstrong\u003echirality-imposed scattering potentials that lift degeneracies and open ΔE ≈ 80 meV gaps\u003c/strong\u003e in the Ag(111) two-dimensional electron gas while leaving the global periodicity intact.\u003c/p\u003e","title":"Chirality in 2D Metal-Organic Framework"},{"content":"Jules has put in the hard yards implementing nanonisTCP as a python module, and leveraged that to create scanbot, a tool for automating the tasks of preparing a good imaging \u0026amp; spectroscopy probe, as well as a suite of functions for performing nuanced, drift-corrected measurements over very long timescales.\nSee the below example of systematically grid scanning 100x100nm images to concatenate a comprehensive view of the surface. Right is the upper left red corner, where self-assembled molecular islands are visible.\nCeddia et al., (2024). Scanbot: An STM Automation Bot. Journal of Open Source Software, 9(99), 6028, https://doi.org/10.21105/joss.06028\n","permalink":"https://jhell.imipolex.biz/2024/07/16/scanbot/","summary":"\u003cp\u003eJules has put in the hard yards implementing \u003ca href=\"https://github.com/New-Horizons-SPM/nanonisTCP\"\u003enanonisTCP\u003c/a\u003e as a python module, and leveraged that to create \u003ca href=\"https://github.com/New-Horizons-SPM/scanbot\"\u003escanbot\u003c/a\u003e, a tool for automating the tasks of preparing a good imaging \u0026amp; spectroscopy probe, as well as a suite of functions for performing nuanced, drift-corrected measurements over very long timescales.\u003c/p\u003e\n\u003cp\u003eSee the below example of systematically grid scanning 100x100nm images to concatenate a comprehensive view of the surface.  Right is the upper left red corner, where self-assembled molecular islands are visible.\u003c/p\u003e","title":"scanbot"},{"content":"Ben \u0026amp; Bernard\u0026#8217;s work on the two-dimensional kagome metal-organic framework is out this week (26 April 2024) in Nature Comms.\nIt was fantastic to see interesting electronic properties emerge at relatively big energy scales for this sort of work, when we were finally able to get the 2d kagome MOF composed of Cu adatoms \u0026amp; DCA molecules, to self-assemble on insulating hexagonal boron nitride (hBN) supported by a Cu111 metallic substrate.\nWe teamed up with Ben Powell\u0026#8217;s group at UQ for the many-body expertise required to understand the tunnel junction and substrate work function dependent modulations of the electronic gap in the language of Mott physics.\nLowe, B., Field, B., Hellerstedt, J.\u0026nbsp;et al.\u0026nbsp;Local gate control of Mott metal-insulator transition in a 2D metal-organic framework.\u0026nbsp;Nat Commun\u0026nbsp;15, 3559 (2024). https://doi.org/10.1038/s41467-024-47766-8\n","permalink":"https://jhell.imipolex.biz/2024/04/30/mott-transition-in-kagome-mof/","summary":"\u003cp\u003e\u003ca href=\"https://www.linkedin.com/in/benjamin-m-lowe/\"\u003eBen\u003c/a\u003e \u0026amp; \u003ca href=\"https://www.linkedin.com/in/bernard-field/\"\u003eBernard\u0026#8217;s\u003c/a\u003e work on the two-dimensional kagome metal-organic framework is out this week (26 April 2024) in \u003ca href=\"https://www.nature.com/articles/s41467-024-47766-8\"\u003eNature Comms\u003c/a\u003e.\u003cbr\u003e\u003cbr\u003eIt was fantastic to see interesting electronic properties emerge at relatively big energy scales for this sort of work, when we were finally able to get the 2d kagome MOF composed of Cu adatoms \u0026amp; DCA molecules, to self-assemble on insulating hexagonal boron nitride (hBN) supported by a Cu111 metallic substrate.\u003cbr\u003e\u003cbr\u003eWe teamed up with \u003ca href=\"https://scholar.google.com.au/citations?user=O02SbzIAAAAJ\u0026amp;hl=en\"\u003eBen Powell\u0026#8217;s\u003c/a\u003e \u003ca href=\"https://people.smp.uq.edu.au/BenPowell/\"\u003egroup at UQ\u003c/a\u003e for the many-body expertise required to understand the tunnel junction and substrate work function dependent modulations of the electronic gap in the language of Mott physics.\u003c/p\u003e","title":"Mott transition in kagome MOF"},{"content":"While pursuing metal-organic frameworks, we stumbled on something unexpected but experimentally robust back in June of 2019. DCA molecules and Au adatoms on Ag111 form DCA-Au-DCA units, and the cyano groups aren\u0026#8217;t involved as you\u0026#8217;d intuitively expect.\nIt took some heroic effort and creative thinking from Adam \u0026amp; the team in Prague to \u0026#8220;just run this one through the computer real quick\u0026#8221;, but nonetheless we\u0026#8217;re pleased to have this explanation of the selective C-H scisson necessary to justify the observed end products.\nLowe, B., et. al. (2022). Selective Activation of Aromatic C–H Bonds Catalyzed by Single Gold Atoms at Room Temperature. J. Am. Chem. Soc. https://doi.org/10.1021/jacs.2c10154\n","permalink":"https://jhell.imipolex.biz/2022/11/20/striped-phase/","summary":"\u003cp\u003eWhile pursuing metal-organic frameworks, we stumbled on something unexpected but experimentally robust back in June of 2019.  DCA molecules and Au adatoms on Ag111 form DCA-Au-DCA units, and the cyano groups aren\u0026#8217;t involved as you\u0026#8217;d intuitively expect.\u003c/p\u003e\n\u003cp\u003eIt took some heroic effort and creative thinking from Adam \u0026amp; the team in Prague to \u0026#8220;just run this one through the computer real quick\u0026#8221;, but nonetheless we\u0026#8217;re pleased to have this explanation of the selective C-H scisson necessary to justify the observed end products.\u003c/p\u003e","title":"Striped Phase"},{"content":"We had the opportunity to use the new toroidal analyzer at the Australian synchrotron to do ARPES of self-assembled monolayers of MgPc on Ag100.\nCareful simultaneous fitting of different high-symmetry EDC measurements, in concert with the structural understanding gleaned from ncAFM \u0026amp; LEED characterization, allowed us to tease out a feature with bandwidth 20 meV, which was surprising to us given that we did the ARPES at room temperature.\nBruce Cowie \u0026amp; Anton Tadich made it possible to break into this kind of measurement with just a week of time; Anton has been instrumental in supporting the analysis that was required to get this one across the finish line.\nHellerstedt, J., et. al. (2022). Direct observation of narrow electronic energy band formation in 2D molecular self-assembly. Nanoscale Advances https://doi.org/10.1039/D2NA00385F\n","permalink":"https://jhell.imipolex.biz/2022/08/18/mgpc-arpes/","summary":"\u003cp\u003eWe had the opportunity to use the\u003ca href=\"https://www.ansto.gov.au/user-access/instruments/australian-synchrotron-beamlines/soft-x-ray-spectroscopy/technical\"\u003e new toroidal analyzer at the Australian synchrotron\u003c/a\u003e to do \u003ca href=\"https://en.wikipedia.org/wiki/Angle-resolved_photoemission_spectroscopy\"\u003eARPES\u003c/a\u003e of self-assembled monolayers of MgPc on Ag100.\u003c/p\u003e\n\u003cdiv class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\"\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"\u003e\n\u003cfigure class=\"wp-block-image size-large\"\u003e\u003cimg fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"671\" src=\"/images/blog/mgpc-arpes/toc-figure.png\" alt=\"\" class=\"wp-image-230\" /\u003e\u003c/figure\u003e\n\u003c/div\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"\u003e\n\u003cp\u003eCareful simultaneous fitting of different high-symmetry EDC measurements, in concert with the structural understanding gleaned from ncAFM \u0026amp; LEED characterization, allowed us to tease out a feature with bandwidth 20 meV, which was surprising to us given that we did the ARPES at room temperature.\u003c/p\u003e","title":"MgPc ARPES"},{"content":"9-azidophenanthrene produces a rich manifold of products when deposited on Ag(111).\nThe images we took for this study inspired this work to develop a lightweight script to count the molecules we observed, and categorize them.\nOur personal journey of computer vision rediscovery led us to Zernike moments, a rotationally invariant basis set that solves the problem of identifying the same molecules with relative rotations, in an image.\nWe put some effort into making this module user-friendly, the example scripts offer a reasonable template to apply to any old SXM file you might want to histogram.\nHellerstedt, J., et. al. (2022). Counting Molecules: Python based scheme for automated enumeration and categorization of molecules in scanning tunneling microscopy images. Software Impacts https://doi.org/10.1016/j.simpa.2022.100301\ngithub repo\n","permalink":"https://jhell.imipolex.biz/2022/03/09/counting-molecules/","summary":"\u003cp\u003e\u003ca href=\"https://pubchem.ncbi.nlm.nih.gov/compound/9-Azidophenanthrene\"\u003e9-azidophenanthrene\u003c/a\u003e produces a \u003ca href=\"http://doi.org/10.1002/anie.201812334\"\u003erich manifold of products\u003c/a\u003e when deposited on Ag(111).\u003cbr\u003e\u003cbr\u003eThe images we took for this study inspired this work to develop a lightweight script to count the molecules we observed, and categorize them.\u003cbr\u003e\u003cbr\u003eOur personal journey of computer vision rediscovery led us to \u003ca href=\"https://en.wikipedia.org/wiki/Zernike_polynomials\"\u003eZernike moments\u003c/a\u003e, a rotationally invariant basis set that solves the problem of identifying the same molecules with relative rotations, in an image.\u003cbr\u003e\u003cbr\u003eWe put some effort into making \u003ca href=\"https://github.com/thennen/counting-molecules\"\u003ethis module\u003c/a\u003e user-friendly, the \u003ca href=\"https://github.com/thennen/counting-molecules/tree/master/examples\"\u003eexample scripts\u003c/a\u003e offer a reasonable template to apply to any old SXM file you might want to histogram.\u003c/p\u003e","title":"Counting Molecules"},{"content":"The AIP summer meeting was a hybrid event this year 6-9 Dec. \u0026#8217;21 with the border restrictions still in place preventing us from travelling to Brisbane.\nIolanda kindly invited me to talk about Marina\u0026#8217;s MgPc hybridization work as well as new results of orbital tomography performed at the Australian Synchrotron (in preparation).\nBen Lowe contributed a talk to the scanning probe microscopy focus session, with an update on how we\u0026#8217;re closing in on understanding the mechanism of formation for some unusual metal-organic products identified with ncAFM measurements.\nThanks also to Peggy Schönherr, Peggy Zhang, Peter Jacobson, and Iolanda DiBernardo for contributing talks to the SPM focus session.\nBernard Field talked about how he\u0026#8217;s pushing forward how we can rationalise our observations of self-assembled MOF structures, stemming from our recently published experimental results that Agustin talked about in the MOF focus session.\n","permalink":"https://jhell.imipolex.biz/2021/12/13/2021-aip-summer-meeting/","summary":"\u003cp\u003eThe \u003ca rel=\"noreferrer noopener\" href=\"https://aip-summer-meeting.com/\" target=\"_blank\"\u003eAIP summer meeting\u003c/a\u003e was a hybrid event this year 6-9 Dec. \u0026#8217;21 with the border restrictions still in place preventing us from travelling to Brisbane.\u003cbr\u003e\u003cbr\u003e\u003ca rel=\"noreferrer noopener\" href=\"https://scholar.google.com/citations?user=G9WqskcAAAAJ\u0026amp;hl=en\" target=\"_blank\"\u003eIolanda\u003c/a\u003e kindly invited me to talk about \u003ca rel=\"noreferrer noopener\" href=\"/2021/02/13/mgpc-mgpc-hybridization/\" target=\"_blank\"\u003eMarina\u0026#8217;s MgPc hybridization work\u003c/a\u003e as well as new results of \u003ca rel=\"noreferrer noopener\" href=\"https://www.science.org/cgi/doi/10.1126/science.1176105\" target=\"_blank\"\u003eorbital tomography\u003c/a\u003e performed at the \u003ca rel=\"noreferrer noopener\" href=\"https://www.ansto.gov.au/research/facilities/australian-synchrotron/overview\" target=\"_blank\"\u003eAustralian Synchrotron\u003c/a\u003e (in preparation).\u003cbr\u003e\u003cbr\u003e\u003ca rel=\"noreferrer noopener\" href=\"https://au.linkedin.com/in/benjamin-m-lowe\" target=\"_blank\"\u003eBen Lowe\u003c/a\u003e contributed a talk to the scanning probe microscopy focus session, with an update on how we\u0026#8217;re closing in on understanding the mechanism of formation for some unusual metal-organic products identified with \u003ca href=\"https://en.wikipedia.org/wiki/Non-contact_atomic_force_microscopy\" target=\"_blank\" rel=\"noreferrer noopener\"\u003encAFM\u003c/a\u003e measurements.\u003cbr\u003e\u003cbr\u003eThanks also to \u003ca rel=\"noreferrer noopener\" href=\"https://au.linkedin.com/in/peggy-sch%C3%B6nherr-37a41214a\" target=\"_blank\"\u003ePeggy Schönherr\u003c/a\u003e, \u003ca rel=\"noreferrer noopener\" href=\"https://scholar.google.com/citations?user=UfDFTz0AAAAJ\u0026amp;hl=en\" target=\"_blank\"\u003ePeggy Zhang\u003c/a\u003e, \u003ca rel=\"noreferrer noopener\" href=\"https://smp.uq.edu.au/profile/7359/peter-jacobson\" target=\"_blank\"\u003ePeter Jacobson\u003c/a\u003e, and \u003ca rel=\"noreferrer noopener\" href=\"https://scholar.google.com/citations?user=G9WqskcAAAAJ\u0026amp;hl=en\" target=\"_blank\"\u003eIolanda DiBernardo\u003c/a\u003e for contributing talks to the SPM focus session.\u003cbr\u003e\u003cbr\u003e\u003ca rel=\"noreferrer noopener\" href=\"https://au.linkedin.com/in/bernard-field-808453209\" target=\"_blank\"\u003eBernard Field\u003c/a\u003e talked about how he\u0026#8217;s pushing forward how we can rationalise our observations of self-assembled MOF structures, stemming from our \u003ca href=\"/2021/09/13/kagome-metal-organic-framework/\"\u003erecently published experimental results\u003c/a\u003e that \u003ca rel=\"noreferrer noopener\" href=\"https://nano.physics.monash.edu/\" target=\"_blank\"\u003eAgustin\u003c/a\u003e talked about in the MOF focus session.\u003cbr\u003e\u003cbr\u003e\u003c/p\u003e","title":"2021 AIP summer meeting"},{"content":" Dhaneesh Kumar has extensively studied the on-surface properties of the DCA molecule for his PhD. After getting a good handle on just the DCA on Ag111, we started sprinkling some Cu atoms into the mix.\nWe observed the same honeycomb kagome structure that forms on Cu111\u0026#8211; as seen in an ncAFM force volume shown in the right image. It has also been synthesized on graphene.\nThe key difference we observed on Ag111 was the Kondo effect, an STS peak at Fermi we tracked up to 150 K!\nThe consistent spatial distribution of this feature across the MOF was another key observation.\nncAFM force volume of DCA (structure superimposed upper right) self-assembly on Cu111 surface. dZ denotes lift of sensor away from surface for each frame. Bernard put in the hard yards with DFT/ +U calculations in conjunction with mean-field Hubbard modelling to rationalise our experimental observations as strong Coulomb interactions between electrons within the kagome MOF.\ndI/dV STS mapping at biases indicated upper left Schematic of Kondo screened spin moments within the MOF. Blender by Dhaneesh We\u0026#8217;re excited by the possibilities for solid-state architectures to offer further access \u0026amp; control of these intriguing quantum states.\nKumar, D., et. al. (2021). Manifestation of Strongly Correlated Electrons in a 2D Kagome Metal–Organic Framework. Advanced Functional Materials, 2106474. https://doi.org/10.1002/adfm.202106474\nArXiv link\nFLEET blog\n","permalink":"https://jhell.imipolex.biz/2021/09/13/kagome-metal-organic-framework/","summary":"\u003cdiv class=\"post-thumbnail\"\u003e\n\t\t\t\u003cimg width=\"825\" height=\"510\" src=\"/images/blog/kagome-metal-organic-framework/kagome-mof-schematic.png\" class=\"attachment-post-thumbnail size-post-thumbnail wp-post-image\" alt=\"DCA Cu Kagome schematic\" decoding=\"async\" fetchpriority=\"high\" /\u003e\t\u003c/div\u003e\n\u003cp\u003e\u003ca href=\"https://scholar.google.com/citations?user=zHayFesAAAAJ\u0026amp;hl=en\u0026amp;oi=ao\" data-type=\"URL\" data-id=\"https://scholar.google.com/citations?user=zHayFesAAAAJ\u0026amp;hl=en\u0026amp;oi=ao\"\u003eDhaneesh Kumar\u003c/a\u003e has extensively studied the on-surface properties of the \u003ca href=\"https://pubchem.ncbi.nlm.nih.gov/compound/9_10-Dicyanoanthracene\" data-type=\"URL\" data-id=\"https://pubchem.ncbi.nlm.nih.gov/compound/9_10-Dicyanoanthracene\"\u003eDCA molecule\u003c/a\u003e for \u003ca href=\"https://bridges.monash.edu/articles/thesis/Atomically_Engineered_Electronic_Two-Dimensional_Organic_Nanostructures/14493825\" data-type=\"URL\" data-id=\"https://bridges.monash.edu/articles/thesis/Atomically_Engineered_Electronic_Two-Dimensional_Organic_Nanostructures/14493825\"\u003ehis PhD\u003c/a\u003e. After getting a good handle on \u003ca rel=\"noreferrer noopener\" href=\"http://doi.org/10.1021/acsnano.9b05950\" target=\"_blank\"\u003ejust the DCA on Ag111\u003c/a\u003e, we started sprinkling some Cu atoms into the mix.\u003c/p\u003e\n\u003cdiv class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\"\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"\u003e\n\u003cp\u003eWe observed the same honeycomb kagome structure that \u003ca rel=\"noreferrer noopener\" href=\"http://doi.wiley.com/10.1002/anie.200802543\" target=\"_blank\"\u003eforms on Cu111\u003c/a\u003e\u0026#8211; as seen in an \u003ca href=\"https://en.wikipedia.org/wiki/Non-contact_atomic_force_microscopy\"\u003encAFM\u003c/a\u003e \u003ca href=\"http://doi.org/10.1103/PhysRevLett.115.076101\"\u003eforce volume\u003c/a\u003e shown in the right image. It has also been \u003ca rel=\"noreferrer noopener\" href=\"https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.202100519\" target=\"_blank\"\u003esynthesized on graphene.\u003c/a\u003e\u003cbr\u003e\u003cbr\u003eThe key difference we observed on Ag111 was the \u003ca href=\"https://en.wikipedia.org/wiki/Kondo_effect\"\u003eKondo effect\u003c/a\u003e, an \u003ca href=\"https://en.wikipedia.org/wiki/Scanning_tunneling_spectroscopy\"\u003eSTS peak\u003c/a\u003e at Fermi we tracked up to 150 K!\u003cbr\u003e\u003cbr\u003eThe consistent spatial distribution of this feature across the MOF was another key observation.\u003c/p\u003e","title":"Kagome metal-organic framework"},{"content":"We stumbled on a very curious observation in the summer of 2018 with DABQDI molecules provided by Olivier Siri\u0026#8216;s team.\nncAFM image of 26 molecule chain. Unfiltered data. Repeated manipulations with STM tip are capable of dragging a DABQDI chain around the Au111 surface. While evaluating its experimental suitability for 1d coordination with metals, which has already proven to be fruitful, we noticed the molecules forming chain-like structures even before we introduced metal adatoms.\nThe low temperature SPM results are sublime: unusual mechanical stability, distinctive intermolecular bonding, and near-Fermi electronic states lighting up at the ends of the chains.\nIt took an extraordinary cast of theorists hailing from Pavel\u0026#8217;s core group, FZU, Charles, Reykjavik, \u0026amp; Madrid Universities to unravel this puzzle and explain these observations as concerted proton tunneling causing a delocalization of electrons.\n\u0026#8220;Significance of Nuclear Quantum Effects in Hydrogen Bonded Molecular Chains\u0026#8221;, ACS Nano, 2021. 10.1021/acsnano.1c02572\nArXiv link\n","permalink":"https://jhell.imipolex.biz/2021/05/26/concerted-proton-transfer/","summary":"\u003cp\u003eWe stumbled on a very curious observation in the summer of 2018 with \u003ca href=\"http://doi.org/10.1016/j.ccr.2017.06.015\"\u003eDABQDI\u003c/a\u003e molecules provided by \u003ca href=\"http://www.cinam.univ-mrs.fr/cinam/le-centre/annuaire/fiche-personnel/?idu=168\"\u003eOlivier Siri\u003c/a\u003e\u0026#8216;s team.\u003c/p\u003e\n\u003cfigure class=\"wp-block-image size-large\"\u003e\u003cimg fetchpriority=\"high\" decoding=\"async\" width=\"774\" height=\"76\" src=\"/images/blog/concerted-proton-transfer/dabqdi-chain-ncafm.png\" alt=\"\" class=\"wp-image-93\" /\u003e\u003cfigcaption\u003encAFM image of 26 molecule chain. Unfiltered data.\u003c/figcaption\u003e\u003c/figure\u003e\n\u003cdiv class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\"\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\"\u003e\n\u003cdiv class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\"\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"\u003e\n\u003cfigure class=\"wp-block-image size-large is-resized\"\u003e\u003cimg decoding=\"async\" src=\"/images/blog/concerted-proton-transfer/dabqdi-stm-manipulation.gif\" alt=\"STM chain manipulation\" class=\"wp-image-91\" width=\"327\" height=\"327\"/\u003e\u003cfigcaption\u003eRepeated manipulations with STM tip are capable of dragging a DABQDI chain around the Au111 surface.\u003c/figcaption\u003e\u003c/figure\u003e\n\u003c/div\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"\u003e\n\u003cp\u003eWhile evaluating its experimental suitability for 1d coordination with metals, \u003ca href=\"http://doi.org/10.1002/anie.202011462\"\u003ewhich has already proven to be fruitful\u003c/a\u003e, we noticed the molecules forming chain-like structures even before we introduced metal adatoms.\u003cbr\u003e\u003cbr\u003eThe low temperature SPM results are sublime: unusual mechanical stability, distinctive intermolecular bonding, and near-Fermi electronic states lighting up at the ends of the chains.\u003c/p\u003e","title":"Concerted Proton Transfer"},{"content":"I\u0026#8217;m presenting Marina\u0026#8217;s work on MgPc hybridization in Focus Session B56 on Monday 15/3 at 1318 (CDT).\nLink to my presentation slides.\nOther talks from our group:\nDhaneesh Kumar, \u0026#8220;Kondo Effect in a 2D Kagome Metal-organic Framework on a Metal\u0026#8221; (15/3 1218 CDT)\nBernard Field, \u0026#8220;Electronic and Magnetic Structure of Metal-Organic Lattices on Substrates\u0026#8221; (15/3 1242 CDT)\nBen Lowe, \u0026#8220;Atomic-Scale Evidence of Surface-Catalyzed Gold-Carbon Covalent Bonding\u0026#8221; (18/3 1206 CDT)\n","permalink":"https://jhell.imipolex.biz/2021/03/12/march-meeting-2021/","summary":"\u003cp\u003eI\u0026#8217;m presenting \u003ca href=\"/2021/02/13/mgpc-mgpc-hybridization/\"\u003eMarina\u0026#8217;s work on MgPc hybridization\u003c/a\u003e in \u003ca href=\"https://meetings.aps.org/Meeting/MAR21/Session/B56.8\"\u003eFocus Session B56\u003c/a\u003e on Monday 15/3 at 1318 (CDT).\u003cbr\u003e\u003cbr\u003e\u003ca href=\"https://docs.google.com/presentation/d/14CQ1wawSgZJtLqBjrY4Tv9_yqapIgrwn6TGzDFIq7CY/edit?usp=sharing\"\u003eLink to my presentation slides.\u003c/a\u003e\u003cbr\u003e\u003cbr\u003eOther talks from our group:\u003cbr\u003e\u003ca href=\"https://scholar.google.com/citations?user=zHayFesAAAAJ\u0026amp;hl=en\u0026amp;oi=ao\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eDhaneesh Kumar\u003c/a\u003e, \u003ca href=\"https://meetings.aps.org/Meeting/MAR21/Session/B56.3\"\u003e\u0026#8220;Kondo Effect in a 2D Kagome Metal-organic Framework on a Metal\u0026#8221;\u003c/a\u003e (15/3 1218 CDT)\u003cbr\u003e\u003cbr\u003eBernard Field, \u003ca href=\"https://meetings.aps.org/Meeting/MAR21/Session/B56.5\"\u003e\u0026#8220;Electronic and Magnetic Structure of Metal-Organic Lattices on Substrates\u0026#8221;\u003c/a\u003e (15/3 1242 CDT)\u003cbr\u003e\u003cbr\u003eBen Lowe, \u003ca href=\"https://meetings.aps.org/Meeting/MAR21/Session/S56.4\"\u003e\u0026#8220;Atomic-Scale Evidence of Surface-Catalyzed Gold-Carbon Covalent Bonding\u0026#8221;\u003c/a\u003e (18/3 1206 CDT)\u003cbr\u003e\u003c/p\u003e","title":"March Meeting 2021"},{"content":" nc-AFM atomic registration of single MgPc molecule on Ag100 (surface atoms top and bottom stripes) Marina Castelli studied the phthalocyanine containing magnesium (MgPc) via 5K scanned probe microscopies extensively during her PhD.\n\u0026#8216;Routine\u0026#8217; STM characterisation showed that the molecules were interacting with one another on the Ag100 surface.\nncAFM showed identical contrast for all molecules, pointing to an electronic origin to the observed changes in appearance.\nOur key observation was to track the shape of the occupied LUMO for different pairwise distances, an electronic feature that otherwise remained isoenergetic.\nWith multipass dI/dV mapping we were able to quantitatively track from four- to two-fold rotational symmetry, over distances out to ~3 nm. We found the spatial extent of this attractive hybridization quite surprising.\n“Long-Range Surface-Assisted Molecule-Molecule Hybridization”,\u0026nbsp;Small (2021). 10.1002/smll.202005974\nFLEET PR\nArXiv link\nSTM image showing the neighbor-induced symmetry reduction ","permalink":"https://jhell.imipolex.biz/2021/02/13/mgpc-mgpc-hybridization/","summary":"\u003cdiv class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\"\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"\u003e\n\u003cfigure class=\"wp-block-image size-large\"\u003e\u003cimg fetchpriority=\"high\" decoding=\"async\" width=\"683\" height=\"1024\" src=\"/images/blog/mgpc-mgpc-hybridization/mgpc-ncafm-registration.png\" alt=\"ncAFM atomic registration of MgPc molecule on Ag100\" class=\"wp-image-44\" /\u003e\u003cfigcaption\u003enc-AFM atomic registration of single MgPc molecule on Ag100 (surface atoms top and bottom stripes)\u003c/figcaption\u003e\u003c/figure\u003e\n\u003c/div\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\"\u003e\n\u003cp\u003eMarina Castelli studied the \u003ca rel=\"noreferrer noopener\" href=\"https://en.wikipedia.org/wiki/Phthalocyanine\" target=\"_blank\"\u003ephthalocyanine\u003c/a\u003e containing magnesium (MgPc) via 5K scanned probe microscopies extensively during her \u003ca rel=\"noreferrer noopener\" href=\"https://doi.org/10.26180/5f598923d1e83\" target=\"_blank\"\u003ePhD.\u003c/a\u003e\u003cbr\u003e\u003cbr\u003e\u0026#8216;Routine\u0026#8217; STM characterisation showed that the molecules were interacting with one another on the Ag100 surface.\u003cbr\u003e\u003cbr\u003e\u003ca rel=\"noreferrer noopener\" href=\"https://en.wikipedia.org/wiki/Non-contact_atomic_force_microscopy\" target=\"_blank\"\u003encAFM\u003c/a\u003e showed identical contrast for all molecules, pointing to an electronic origin to the observed changes in appearance.\u003cbr\u003e\u003cbr\u003eOur key observation was to track the \u003cem\u003eshape\u003c/em\u003e of the occupied LUMO for different pairwise distances, an electronic feature that otherwise remained isoenergetic.\u003c/p\u003e","title":"MgPc-MgPc Hybridization"},{"content":"Iolanda DiBernardo reviewed the development of Na3Bi as a topological electronic material.\nThe physics of Dirac semimetals (\u0026#8220;3d graphene\u0026#8221;) is introduced, and the results from the last half decade are tied together in one narrative, in particular our work at Monash demonstrating that Na3Bi grows directly on insulators, and that indeed an electric field will open a topological gap, two key ingredients to achieving a working \u0026#8220;topological transistor\u0026#8221;.\n\u0026#8220;Progress in Epitaxial Thin‐Film Na3Bi as a Topological Electronic Material\u0026#8221;, Advanced Materials, 2021. 10.1002/adma.202005897\n","permalink":"https://jhell.imipolex.biz/2021/02/05/thin-film-dirac-semimetal-review-article/","summary":"\u003cp\u003e\u003ca rel=\"noreferrer noopener\" href=\"https://scholar.google.com/citations?user=G9WqskcAAAAJ\u0026amp;hl=en\" target=\"_blank\"\u003eIolanda DiBernardo\u003c/a\u003e reviewed the development of Na\u003csub\u003e3\u003c/sub\u003eBi as a topological electronic material.\u003cbr\u003e\u003cbr\u003eThe physics of Dirac semimetals (\u0026#8220;3d graphene\u0026#8221;) is introduced, and the results from the last half decade are tied together in one narrative, in particular our work at Monash demonstrating that \u003ca rel=\"noreferrer noopener\" href=\"http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b00638\" target=\"_blank\"\u003eNa\u003csub\u003e3\u003c/sub\u003eBi grows directly on insulators\u003c/a\u003e, and that indeed an \u003ca rel=\"noreferrer noopener\" href=\"http://www.nature.com/articles/s41586-018-0788-5\" target=\"_blank\"\u003eelectric field will open a topological gap\u003c/a\u003e, two key ingredients to achieving a working \u0026#8220;topological transistor\u0026#8221;.\u003c/p\u003e\n\u003cdiv class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex wp-altmetric-row\"\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:10%\"\u003e\n\u003cscript type=\"text/javascript\" src=\"https://d1bxh8uas1mnw7.cloudfront.net/assets/embed.js\"\u003e\u003c/script\u003e\u003cdiv class=\"altmetric-embed\" data-badge-type=\"donut\" data-doi=\"10.1002/adma.202005897\"\u003e\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:90%\"\u003e\n\u003cp\u003e\u0026#8220;Progress in Epitaxial Thin‐Film Na\u003csub\u003e3\u003c/sub\u003eBi as a Topological Electronic Material\u0026#8221;, Advanced Materials, 2021. \u003ca rel=\"noreferrer noopener\" href=\"https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202005897\" target=\"_blank\"\u003e10.1002/adma.202005897\u003c/a\u003e\u003c/p\u003e","title":"Thin-film Dirac semimetal review article"},{"content":"Professional experience 9/2022 \u0026#8211; 8/2025 Lead Scientist, Wavewise Analytics née Cyban\nLead Scientist\nWavewise Analytics / Cyban\nTeo EJ, Petautschnig S, Chung SW, Hellerstedt J, Savage J, Dixon B. The Development of Non-Invasive Optical Brain Pulse Monitoring: A Review. Med Devices (Auckl). 2024;17:491-511\nhttps://doi.org/10.2147/MDER.S498589\nCerebrovascular Responses in a Patient with Lundberg B Waves Following Subarachnoid Haemorrhage Assessed with a Novel Non-Invasive Brain Pulse Monitor: A Case Report\nDove Press (2024)\nAssessment of a Non-Invasive Brain Pulse Monitor to Measure Intra-Cranial Pressure Following Acute Brain Injury.\nDove Press (2023)\n12/2018 \u0026#8211; 8/2022 Postdoc, Monash University\nPostdoctoral Research Fellow\nSchiffrin group\nTuning Interface Electronic Properties via Chiral Two-Dimensional Metal-Organic Frameworks (2025). Small Structures. https://doi.org/10.1002/sstr.202500422\nblog post\nCeddia et al., (2024). Scanbot: An STM Automation Bot. Journal of Open Source Software, 9(99), 6028, https://doi.org/10.21105/joss.06028\nblog post\n\u0026#8220;Local gate control of Mott metal-insulator transition in a 2D metal-organic framework.\u0026#8221; Nat Comm. (2024).\nblog post\n\u0026#8220;Upper Bound Estimate of the Electronic Scattering Potential of a Weakly Interacting Molecular Film on a Metal\u0026#8221;\nJPCC (2024)\n\u0026#8220;Mesoscopic 2D molecular self-assembly on an insulator\u0026#8221;\nIOP Nanotechnology (2023)\n\u0026#8220;Selective Activation of Aromatic C–H Bonds Catalyzed by Single Gold Atoms at Room Temperature.\u0026#8221;\nJACS (2022)\nblog post\n\u0026#8220;Direct observation of narrow electronic energy band formation in 2D molecular self-assembly.\u0026#8221;\nNanoscale Advances (2022)\nblog post\n\u0026#8220;Manifestation of Strongly Correlated Electrons in a 2D Kagome Metal–Organic Framework\u0026#8221;\nAdv. Func. Mater. (2021)\nblog post\n\u0026#8220;Long-Range Surface-Assisted Molecule-Molecule Hybridization\u0026#8221;\nSmall (2021)\nblog post\n\u0026#8220;Progress in Epitaxial Thin-Film Na3Bi as a Topological Electronic Material\u0026#8221;\nAdvanced Materials (2021)\nblog post\n9/2016 \u0026#8211; 9/2018 Fulbright Scholar + Postdoc, FZU Prague\n9/2016 \u0026#8211; 6/2017 Fulbright Scholar\n9/2016 \u0026#8211; 9/2018 Postdoctoral Research Fellow\nNanosurf Lab\nInstitute of Physics \u0026#8211; Academy of Sciences of the Czech Republic (FZU)\n\u0026#8220;Significance Of Nuclear Quantum Effects In Hydrogen Bonded Molecular Chains\u0026#8221;\nACS Nano (2021)\nblog post\n\u0026#8220;Aromatic Azide Transformation on the Ag(111) Surface Studied by Scanning Probe Microscopy\u0026#8221;\nAngewandte (2019)\n\u0026#8220;Nitrous oxide as an effective AFM tip functionalization: a comparative study\u0026#8221;\nBeilstein J. Nanotechnol. (2019)\n\u0026#8220;On-surface structural and electronic properties of spontaneously formed Tb2Pc3 single molecule magnets\u0026#8221;\nRSC Nanoscale (2018)\n5/2015 \u0026#8211; 9/2016 Postdoc, Monash University\nPostdoctoral Research Fellow\nFuhrer lab\n\u0026#8220;Quantum Transport in Air-Stable Na3Bi Thin Films\u0026#8221;\nACS Appl. Mater. Interfaces (2020)\n\u0026#8220;Electronic Band Structure of In-Plane Ferroelectric van der Waals β′-In2Se3\u0026#8221;\nACS Appl. Electron. Mater. (2020)\n\u0026#8220;Electric-field-tuned topological phase transition in ultrathin Na3Bi\u0026#8221;\nNature (2018)\n\u0026#8220;Iron-based trinuclear metal-organic nanostructures on a surface with local charge accumulation\u0026#8221;\nNature Communications (2018)\n\u0026#8220;Observation of Effective Pseudospin Scattering in ZrSiS\u0026#8221;\nNano Lett. (2017)\n\u0026#8220;Temperature-dependent n−p transition in a three-dimensional Dirac semimetal Na3Bi thin film\u0026#8221;\nPhys. Rev. B (2017)\n\u0026#8220;Spatial charge inhomogeneity and defect states in topological Dirac semimetal thin films of Na3Bi\u0026#8221;\nScience Advances (2017)\n\u0026#8220;Electrostatic modulation of the electronic properties of Dirac semimetal Na3Bi thin films\u0026#8221;\nPhys. Rev. Materials (2017)\n\u0026#8220;Polypyridyl Iron Complex as a Hole-Transporting Material for Formamidinium Lead Bromide Perovskite Solar Cells\u0026#8221;\nACS Energy Lett. (2017)\n\u0026#8220;Direct Observation of 2D Electrostatics and Ohmic Contacts in Template-Grown Graphene/WS2 Heterostructures\u0026#8221;\nACS Nano (2017)\n\u0026#8220;Cobalt Polypyridyl Complexes as Transparent Solution-Processable Solid-State Charge Transport Materials\u0026#8221;\nAdv. Eng. Mat (2016)\n\u0026#8220;Catastrophic degradation of the interface of epitaxial silicon carbide on silicon at high temperatures\u0026#8221;\nAppl. Phys. Lett. (2016)\n\u0026#8220;Molecular Doping the Topological Dirac Semimetal Na3Bi across the Charge Neutrality Point with F4-TCNQ\u0026#8221;\nACS Appl. Mater. Interfaces (2016)\n6/2010 \u0026#8211; 5/2015 Graduate Student, University of Maryland\nFuhrer lab\n6/2010 \u0026#8211; 12/2012, University of Maryland, College Park\n2/2013 \u0026#8211; 5/2015, School of Physics, Monash University\n\u0026#8220;Electronic Properties of High-Quality Epitaxial Topological Dirac Semimetal Thin Films\u0026#8221;\nNano Lett. (2016)\n\u0026#8220;Thickness and growth-condition dependence of in-situ mobility and carrier density of epitaxial thin-film Bi2Se3\u0026#8220;\nAppl. Phys. Lett. (2014)\n\u0026#8220;Stability and Surface Reconstruction of Topological Insulator Bi2Se3 on Exposure to Atmosphere\u0026#8221;\nJ. Phys. Chem. C (2014)\n\u0026#8220;Air-Stable Electron Depletion of Bi2Se3 Using Molybdenum Trioxide into the Topological Regime\u0026#8221;\nACS Nano (2014)\n6/2014 \u0026#8211; 8/2014 NSF EAPSI / JSPS Summer Research Fellowship\nHasegawa group\nInstitute for Solid State Physics, University of Tokyo\n2007 \u0026#8211; 2010 Undergraduate Research, University of Minnesota\nGoldman group; vale Allen\n\u0026#8220;Phase Diagram of Electrostatically Doped SrTiO3\u0026#8221; Phys. Rev. Lett. (2011)\nSupervision PhD (Monash)\nCompleted 5/2025 Julian Ceddia (25% w/ Agustin Schiffrin; supervised until 8/22)\n\u0026#8220;Engineering and Control of Two-Dimensional Molecular Nanoarchitectures for Future Electronics\u0026#8221;\n11/2023 Benjamin Lowe (25% w/ Agustin Schiffrin)\n\u0026#8220;Atomic-Scale Control of Metal-Organic Nanostructures for Electronics\u0026#8221;\n5/2021 Dhaneesh Kumar (20% w/ Agustin Schiffrin)\n\u0026#8220;Atomically Engineered Electronic Two-Dimensional Organic Nanostructures\u0026#8221;\n9/2020 Marina Castelli (25% w/ Agustin Schiffrin)\n\u0026#8220;Atomically precise low-dimensional metal-organic nanostructures with tailored electronic properties\u0026#8221; Honours (Monash)\nCompleted 12/2020 Kushagra Khare (20% w/ Agustin Schiffrin) 12/2019 Benjamin Lowe (20% w/ Agustin Schiffrin) Teaching 2020 \u0026amp; 2021 Honours Condensed Matter Physics sub-unit\nPHS4200 Condensed Matter Physics sub-unit (mesoscopic physics half, shared with Agustin Schiffrin).\nEducation 6/2010 \u0026#8211; 5/2015 PhD Physics\nUniversity of Maryland, College Park\nThesis:\nIn Situ Growth and Doping Studies of Topological Insulator Bismuth Selenide\n9/2006 \u0026#8211; 5/2010 BS Physics, Mathematics\nUniversity of Minnesota, Twin Cities\n","permalink":"https://jhell.imipolex.biz/about-cv/","summary":"\u003ch2 class=\"wp-block-heading\"\u003eProfessional experience\u003c/h2\u003e\n\u003cdiv class=\"wp-block-ub-content-toggle wp-block-ub-content-toggle-block\" id=\"ub-content-toggle-block-a7311ffe-0e2b-4b67-9370-a5fe67949ca0\" data-mobilecollapse=\"false\" data-desktopcollapse=\"true\" data-preventcollapse=\"false\" data-showonlyone=\"false\"\u003e\n\u003cdiv class=\"wp-block-ub-content-toggle-accordion\" style=\"border-color: #f1f1f1; \" id=\"ub-content-toggle-panel-block-cbf1c564-e508-4b3c-8d7a-e38916634232\"\u003e\n\t\t\t\u003cdiv class=\"wp-block-ub-content-toggle-accordion-title-wrap\" style=\"background-color: #f1f1f1;\" aria-controls=\"ub-content-toggle-panel-0-a7311ffe-0e2b-4b67-9370-a5fe67949ca0\" tabindex=\"0\"\u003e\n\t\t\t\u003cp class=\"wp-block-ub-content-toggle-accordion-title ub-content-toggle-title-a7311ffe-0e2b-4b67-9370-a5fe67949ca0\" style=\"color: #000000; \"\u003e9/2022 \u0026#8211; 8/2025 Lead Scientist, Wavewise Analytics née Cyban\u003c/p\u003e\n\t\t\t\u003cdiv class=\"wp-block-ub-content-toggle-accordion-toggle-wrap right\" style=\"color: #000000;\"\u003e\u003cspan class=\"wp-block-ub-content-toggle-accordion-state-indicator wp-block-ub-chevron-down\"\u003e\u003c/span\u003e\u003c/div\u003e\n\t\t\u003c/div\u003e\n\t\t\t\u003cdiv role=\"region\" aria-expanded=\"false\" class=\"wp-block-ub-content-toggle-accordion-content-wrap ub-hide\" id=\"ub-content-toggle-panel-0-a7311ffe-0e2b-4b67-9370-a5fe67949ca0\"\u003e\n\u003cp\u003eLead Scientist\u003cbr\u003e\u003ca href=\"http://wavewise.com\" data-type=\"link\" data-id=\"wavewise.com\"\u003eWavewise Analytics\u003c/a\u003e / \u003ca href=\"https://www.cyban.com.au/\"\u003eCyban\u003c/a\u003e\u003c/p\u003e\n\u003cdiv class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex wp-altmetric-row\"\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:10%\"\u003e\n\u003cscript type=\"text/javascript\" src=\"https://d1bxh8uas1mnw7.cloudfront.net/assets/embed.js\"\u003e\u003c/script\u003e\u003cdiv class=\"altmetric-embed\" data-badge-type=\"donut\" data-doi=\"10.2147/MDER.S49858\"\u003e\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:90%\"\u003e\n\u003cp\u003eTeo EJ, Petautschnig S, Chung SW, Hellerstedt J, Savage J, Dixon B. The Development of Non-Invasive Optical Brain Pulse Monitoring: A Review. \u003cem\u003eMed Devices (Auckl)\u003c/em\u003e. 2024;17:491-511\u003cbr\u003e\u003ca href=\"https://doi.org/10.2147/MDER.S498589\"\u003ehttps://doi.org/10.2147/MDER.S498589\u003c/a\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex wp-altmetric-row\"\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:10%\"\u003e\n\u003cscript type=\"text/javascript\" src=\"https://d1bxh8uas1mnw7.cloudfront.net/assets/embed.js\"\u003e\u003c/script\u003e\u003cdiv class=\"altmetric-embed\" data-badge-type=\"donut\" data-doi=\"10.2147/MDER.S452938\"\u003e\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:90%\"\u003e\n\u003cp\u003eCerebrovascular Responses in a Patient with Lundberg B Waves Following Subarachnoid Haemorrhage Assessed with a Novel Non-Invasive Brain Pulse Monitor: A Case Report\u003cbr\u003e\u003ca href=\"https://www.dovepress.com/articles.php?article_id=90560\"\u003eDove Press (2024)\u003c/a\u003e\u003c/p\u003e","title":"about / cv"},{"content":"Neutral atomsQuantum computingQuantum journalsScience techSpin qubits ","permalink":"https://jhell.imipolex.biz/feeds/","summary":"\u003cul class=\"rss-feed-list\"\u003e\u003cli\u003e\u003ca href=\"/rss/neutral_atoms.xml\"\u003eNeutral atoms\u003c/a\u003e\u003c/li\u003e\u003cli\u003e\u003ca href=\"/rss/quantum_computing.xml\"\u003eQuantum computing\u003c/a\u003e\u003c/li\u003e\u003cli\u003e\u003ca href=\"/rss/quantum_journals.xml\"\u003eQuantum journals\u003c/a\u003e\u003c/li\u003e\u003cli\u003e\u003ca href=\"/rss/science_tech.xml\"\u003eScience tech\u003c/a\u003e\u003c/li\u003e\u003cli\u003e\u003ca href=\"/rss/spin_qubits.xml\"\u003eSpin qubits\u003c/a\u003e\u003c/li\u003e\u003c/ul\u003e","title":"Feeds"},{"content":" Optical Brain Pulse Monitoring (OBPM)\nTeo EJ, Petautschnig S, Chung SW, Hellerstedt J, Savage J, Dixon B. The Development of Non-Invasive Optical Brain Pulse Monitoring: A Review. Med Devices (Auckl). 2024;17:491-511\nhttps://doi.org/10.2147/MDER.S498589\nIntracranial Pressure (ICP)\nMeasurement of intracranial pressure is typically done via an invasive probe.\nCerebrovascular Responses in a Patient with Lundberg B Waves Following Subarachnoid Haemorrhage Assessed with a Novel Non-Invasive Brain Pulse Monitor: A Case Report\nDove Press (2024)\nAssessment of a Non-Invasive Brain Pulse Monitor to Measure Intra-Cranial Pressure Following Acute Brain Injury.\u0026#8221;\nDove Press (2023)\nMetal-organic frameworks (MOF)\nSelf-assembly at the nanoscale means using the nearly limitless library of organic molecules as building blocks to ideally engineer the electronic phenomena that emerge from the periodic patterns they form.\nOne such example is our work attributing the Kondo effect we measured in a substrate supported metal-organic framework to a strongly correlated electron state existing in the MOF.\nTuning Interface Electronic Properties via Chiral Two-Dimensional Metal-Organic Frameworks (2025). Small Structures. https://doi.org/10.1002/sstr.202500422\nblog post\nLowe, B., Field, B., Hellerstedt, J. et al. Local gate control of Mott metal-insulator transition in a 2D metal-organic framework. Nat Commun 15, 3559 (2024). https://doi.org/10.1038/s41467-024-47766-8\n\u0026#8220;Manifestation of Strongly Correlated Electrons in a 2D Kagome Metal–Organic Framework\u0026#8221;\nAdv. Func. Mater. (2021)\nblog post\nSubstrate-molecule effects, on-surface chemistry\nThere\u0026#8217;s plenty of room at the bottom\nRichard Feynman The invention of scanning tunneling microscopy and more recently, non-contact atomic force microscopy, has made the observation and manipulation of single atoms and molecules a routine exercise.\nThis work is at the intersection of chemistry \u0026amp; physics, with diverse messages reflecting the high likelihood for observing unexpected results even with tightly controlled ingredients and experimental circumstances.\n\u0026#8220;Upper Bound Estimate of the Electronic Scattering Potential of a Weakly Interacting Molecular Film on a Metal\u0026#8221;\nJPCC (2024)\n\u0026#8220;Mesoscopic 2D molecular self-assembly on an insulator\u0026#8221;\nIOP Nanotechnology (2023)\n\u0026#8220;Selective Activation of Aromatic C–H Bonds Catalyzed by Single Gold Atoms at Room Temperature.\u0026#8221;\nJACS (2022)\nblog post\n\u0026#8220;Direct observation of narrow electronic energy band formation in 2D molecular self-assembly.\u0026#8221;\nNanoscale Advances (2022)\nblog post\n\u0026#8220;Long-Range Surface-Assisted Molecule-Molecule Hybridization\u0026#8221;\nSmall (2021)\nblog post\n\u0026#8220;Significance Of Nuclear Quantum Effects In Hydrogen Bonded Molecular Chains\u0026#8221;\nACS Nano (2021)\nblog post\n\u0026#8220;Aromatic Azide Transformation on the Ag(111) Surface Studied by Scanning Probe Microscopy\u0026#8221;\nAngewandte (2019)\n\u0026#8220;Nitrous oxide as an effective AFM tip functionalization: a comparative study\u0026#8221;\nBeilstein J. Nanotechnol. (2019)\n\u0026#8220;Iron-based trinuclear metal-organic nanostructures on a surface with local charge accumulation\u0026#8221;\nNature Communications (2018)\n\u0026#8220;On-surface structural and electronic properties of spontaneously formed Tb2Pc3 single molecule magnets\u0026#8221;\nRSC Nanoscale (2018)\nTopological Dirac Semimetal Na3Bi\nWe applied the methodology developed for Bi2Se3 to the Dirac semimetal Na3Bi with remarkable success. These are materials where band inversion near the Fermi level creates Dirac-like \u0026#8220;cones\u0026#8221;, a 3d version of the dispersion that made graphene famous.\nWe demonstrated large-area thin-film growth, with control in the regime where we could electrostatically control the presence of a topological gap, experimental proof-of-concept to build a topological transistor.\nWe demonstrated the efficacy of MgF2 as a stabilising capping layer, opening the door to possibilities for Na3Bi beyond just a UHV curiousity.\n\u0026#8220;Progress in Epitaxial Thin-Film Na3Bi as a Topological Electronic Material\u0026#8221;\nAdvanced Materials (2021)\nblog post\n\u0026#8220;Quantum Transport in Air-Stable Na3Bi Thin Films\u0026#8221;\nACS Appl. Mater. Interfaces (2020)\n\u0026#8220;Electric-field-tuned topological phase transition in ultrathin Na3Bi\u0026#8221;\nNature (2018)\n\u0026#8220;Temperature-dependent n−p transition in a three-dimensional Dirac semimetal Na3Bi thin film\u0026#8221;\nPhys. Rev. B (2017)\n\u0026#8220;Spatial charge inhomogeneity and defect states in topological Dirac semimetal thin films of Na3Bi\u0026#8221;\nScience Advances (2017)\n\u0026#8220;Electrostatic modulation of the electronic properties of Dirac semimetal Na3Bi thin films\u0026#8221;\nPhys. Rev. Materials (2017)\n\u0026#8220;Molecular Doping the Topological Dirac Semimetal Na3Bi across the Charge Neutrality Point with F4-TCNQ\u0026#8221;\nACS Appl. Mater. Interfaces (2016)\n\u0026#8220;Electronic Properties of High-Quality Epitaxial Topological Dirac Semimetal Thin Films\u0026#8221;\nNano Lett. (2016)\nTopological Insulator Bi2Se3\nMy thesis research focussed on the seminal topological insulator Bi2Se3. With the apparatus we developed we were able to show that significant doping is present as soon as the TI is grown on substrate, before exposure to atmosphere. We demonstrated that electron acceptor MoO3 can mitigate this effect and stabilise the TI in atmosphere.\n\u0026#8220;Thickness and growth-condition dependence of in-situ mobility and carrier density of epitaxial thin-film Bi2Se3\u0026#8220;\nAppl. Phys. Lett. (2014)\n\u0026#8220;Stability and Surface Reconstruction of Topological Insulator Bi2Se3 on Exposure to Atmosphere\u0026#8221;\nJ. Phys. Chem. C (2014)\n\u0026#8220;Air-Stable Electron Depletion of Bi2Se3 Using Molybdenum Trioxide into the Topological Regime\u0026#8221;\nACS Nano (2014)\nInstrumentation \u0026amp; Software\nCeddia et al., (2024). Scanbot: An STM Automation Bot. Journal of Open Source Software, 9(99), 6028, https://doi.org/10.21105/joss.06028\nblog post\nHellerstedt, J., et. al. (2022). Counting Molecules: Python based scheme for automated enumeration and categorization of molecules in scanning tunneling microscopy images. Software Impacts https://doi.org/10.1016/j.simpa.2022.100301\ngithub repo\nblog post\n","permalink":"https://jhell.imipolex.biz/research/","summary":"\u003cdiv class=\"wp-block-ub-content-toggle wp-block-ub-content-toggle-block\" id=\"ub-content-toggle-block-a5b1e3c6-68e9-4e48-a443-ae8dbd2f702d\" data-mobilecollapse=\"false\" data-desktopcollapse=\"true\" data-preventcollapse=\"false\" data-showonlyone=\"false\"\u003e\n\u003cdiv class=\"wp-block-ub-content-toggle-accordion\" style=\"border-color: #f1f1f1; \" id=\"ub-content-toggle-panel-block-66392439-faaf-4f79-b485-92b7ef5ec2f0\"\u003e\n\t\t\t\u003cdiv class=\"wp-block-ub-content-toggle-accordion-title-wrap\" style=\"background-color: #f1f1f1;\" aria-controls=\"ub-content-toggle-panel-0-a5b1e3c6-68e9-4e48-a443-ae8dbd2f702d\" tabindex=\"0\"\u003e\n\t\t\t\u003cp class=\"wp-block-ub-content-toggle-accordion-title ub-content-toggle-title-a5b1e3c6-68e9-4e48-a443-ae8dbd2f702d\" style=\"color: #000000; \"\u003eOptical Brain Pulse Monitoring (OBPM)\u003c/p\u003e\n\t\t\t\u003cdiv class=\"wp-block-ub-content-toggle-accordion-toggle-wrap right\" style=\"color: #000000;\"\u003e\u003cspan class=\"wp-block-ub-content-toggle-accordion-state-indicator wp-block-ub-chevron-down\"\u003e\u003c/span\u003e\u003c/div\u003e\n\t\t\u003c/div\u003e\n\t\t\t\u003cdiv role=\"region\" aria-expanded=\"false\" class=\"wp-block-ub-content-toggle-accordion-content-wrap ub-hide\" id=\"ub-content-toggle-panel-0-a5b1e3c6-68e9-4e48-a443-ae8dbd2f702d\"\u003e\n\u003cp\u003e\u003c/p\u003e\n\u003cdiv class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex wp-altmetric-row\"\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:10%\"\u003e\n\u003cscript type=\"text/javascript\" src=\"https://d1bxh8uas1mnw7.cloudfront.net/assets/embed.js\"\u003e\u003c/script\u003e\u003cdiv class=\"altmetric-embed\" data-badge-type=\"donut\" data-doi=\"10.2147/MDER.S49858\"\u003e\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:90%\"\u003e\n\u003cp\u003eTeo EJ, Petautschnig S, Chung SW, Hellerstedt J, Savage J, Dixon B. The Development of Non-Invasive Optical Brain Pulse Monitoring: A Review. \u003cem\u003eMed Devices (Auckl)\u003c/em\u003e. 2024;17:491-511\u003cbr\u003e\u003ca href=\"https://doi.org/10.2147/MDER.S498589\"\u003ehttps://doi.org/10.2147/MDER.S498589\u003c/a\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003c/p\u003e\n\u003c/div\u003e\n\t\t\u003c/div\u003e\n\u003cdiv class=\"wp-block-ub-content-toggle-accordion\" style=\"border-color: #f1f1f1; \" id=\"ub-content-toggle-panel-block-66392439-faaf-4f79-b485-92b7ef5ec2f0\"\u003e\n\t\t\t\u003cdiv class=\"wp-block-ub-content-toggle-accordion-title-wrap\" style=\"background-color: #f1f1f1;\" aria-controls=\"ub-content-toggle-panel-1-a5b1e3c6-68e9-4e48-a443-ae8dbd2f702d\" tabindex=\"0\"\u003e\n\t\t\t\u003cp class=\"wp-block-ub-content-toggle-accordion-title ub-content-toggle-title-a5b1e3c6-68e9-4e48-a443-ae8dbd2f702d\" style=\"color: #000000; \"\u003eIntracranial Pressure (ICP)\u003c/p\u003e\n\t\t\t\u003cdiv class=\"wp-block-ub-content-toggle-accordion-toggle-wrap right\" style=\"color: #000000;\"\u003e\u003cspan class=\"wp-block-ub-content-toggle-accordion-state-indicator wp-block-ub-chevron-down\"\u003e\u003c/span\u003e\u003c/div\u003e\n\t\t\u003c/div\u003e\n\t\t\t\u003cdiv role=\"region\" aria-expanded=\"false\" class=\"wp-block-ub-content-toggle-accordion-content-wrap ub-hide\" id=\"ub-content-toggle-panel-1-a5b1e3c6-68e9-4e48-a443-ae8dbd2f702d\"\u003e\n\u003cp\u003eMeasurement of intracranial pressure is typically done via an invasive probe.\u003c/p\u003e","title":"research"}]