Serghei N. Klimin, Jacques Tempere, Matthew Houtput, Stefano Ragni, Thomas Hahn, Cesare Franchini, Andrey S. Mishchenko
Including the effect of lattice anharmonicity on electron-phonon interactions has recently garnered attention due to its role as a necessary and significant component in explaining various phenomena, including superconductivity, optical response, and the temperature dependence of mobility. This study focuses on analytically treating the effects of anharmonic electron-phonon coupling on the polaron self-energy, combined with numerical Diagrammatic Monte Carlo data. Specifically, we incorporate a quadratic interaction into the method of squeezed phonon states, which has proven effective for analytically calculating the polaron parameters. Additionally, we extend this method to non-parabolic finite-width conduction bands while maintaining the periodic translation symmetry of the system. Our results are compared with those obtained from Diagrammatic Monte Carlo, partially reported in a recent study [Phys. Rev. B 107, L121109(2023)], covering a wide range of coupling strengths for the nonlinear interaction. Remarkably, our analytic method predicts the same features as the Diagrammatic Monte Carlo simulation.
晶格非谐波对电子-声子相互作用的影响最近引起了人们的关注，因为它是解释各种现象（包括超导性、光学响应和迁移率的温度依赖性）的一个必要和重要的组成部分。这项研究的重点是分析处理非谐波电子-声子耦合对极子自能的影响，并结合数值图解蒙特卡洛数据。具体来说，我们将二次相互作用纳入挤压声子态方法，该方法已被证明对分析计算极子参数非常有效。此外，我们在保持系统周期性平移对称性的同时，将这种方法扩展到了非抛物面无限宽导带。我们的结果与最近的一项研究[Phys. Rev. B107, L121109(2023)]中部分报道的从模拟蒙特卡洛（Diagrammatic Monte Carlo）得到的结果进行了比较，后者涵盖了当时非线性相互作用的宽耦合强度范围。值得注意的是，我们的分析方法预测了与图解蒙特卡罗模拟相同的特征。
{"title":"An analytic method for quadratic polarons in non-parabolic bands","authors":"Serghei N. Klimin, Jacques Tempere, Matthew Houtput, Stefano Ragni, Thomas Hahn, Cesare Franchini, Andrey S. Mishchenko","doi":"arxiv-2403.18019","DOIUrl":"https://doi.org/arxiv-2403.18019","url":null,"abstract":"Including the effect of lattice anharmonicity on electron-phonon interactions\u0000has recently garnered attention due to its role as a necessary and significant\u0000component in explaining various phenomena, including superconductivity, optical\u0000response, and the temperature dependence of mobility. This study focuses on\u0000analytically treating the effects of anharmonic electron-phonon coupling on the\u0000polaron self-energy, combined with numerical Diagrammatic Monte Carlo data.\u0000Specifically, we incorporate a quadratic interaction into the method of\u0000squeezed phonon states, which has proven effective for analytically calculating\u0000the polaron parameters. Additionally, we extend this method to non-parabolic\u0000finite-width conduction bands while maintaining the periodic translation\u0000symmetry of the system. Our results are compared with those obtained from\u0000Diagrammatic Monte Carlo, partially reported in a recent study [Phys. Rev. B\u0000107, L121109(2023)], covering a wide range of coupling strengths for the\u0000nonlinear interaction. Remarkably, our analytic method predicts the same\u0000features as the Diagrammatic Monte Carlo simulation.","PeriodicalId":501211,"journal":{"name":"arXiv - PHYS - Other Condensed Matter","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we report the growth of a single mixed Bi$_{1-x}$Sb$_x$ layer, with diverse stoichiometries, on a Ag(111) substrate. The atomic geometry has been thoroughly investigated by low energy electron diffraction, scanning tunneling microscopy, and X-ray photoelectron spectroscopy experiments, as well as calculations based on density functional theory (DFT). We first determined that both pure systems (Bi/Ag(111) and Sb/Ag(111)) show similar behaviors: they form surface alloys with ($sqrt{3}timessqrt{3}$)R30$^circ$ periodicity for coverages lower than 1/3 ML, and undergo a dealloying transition for higher coverages up to 2/3 ML. We then established a simple preparation procedure to obtain a mixed Bi-Sb overlayer on Ag(111): it is essential to start with a surface completely covered by either of the two pure surface alloys and then deposit the other element on it. The energetics derived from DFT calculations provide insight into the systems preference towards the formation of this phase, and also predict a pathway to the formation of Bi-rich non-alloyed phases. The obtained mixed Bi-Sb phase has a lateral atomic arrangement very similar to the one in the non-alloyed phase observed for Sb on Ag(111), with Sb and Bi atoms distributed disorderly, and presents a significant vertical corrugation, promising considerable Rashba effects.
在这项工作中，我们报告了在 Ag(111) 基质上生长出具有不同化学计量的单一混合 Bi$_{1-x}$Sb$_x$ 层的情况。通过低能电子衍射、扫描隧道显微镜和 X 射线光电子能谱实验以及基于密度泛函理论（DFT）的计算，我们对原子几何结构进行了深入研究。我们首先确定这两种纯体系（Bi/Ag(111) 和 Sb/Ag(111)）表现出相似的行为：在覆盖率低于 1/3 ML 时，它们会形成具有 ($sqrt{3}timessqrt{3}$)R30$^circ$ 周期性的表面合金；而在覆盖率高达 2/3 ML 时，它们会发生脱合金转变。然后，我们建立了在 Ag(111) 上获得铋锑混合覆盖层的简单制备程序：必须先从完全被两种纯表面合金中的任何一种覆盖的表面开始，然后在其上沉积另一种元素。通过 DFT 计算得出的能量学说深入揭示了系统对形成该相的偏好，并预测了富铋非合金相的形成途径。所得到的铋锑混合相的横向原子排列与在 Ag(111) 上观察到的锑非合金相的原子排列非常相似，锑原子和铋原子无序分布，并呈现出明显的垂直波纹，有望产生相当大的拉什巴效应。
{"title":"Single-layer of Bi$_{1-x}$Sb$_x$ grown on Ag(111)","authors":"Javier D. Fuhr, J. Esteban Gayone, Hugo Ascolani","doi":"arxiv-2403.15242","DOIUrl":"https://doi.org/arxiv-2403.15242","url":null,"abstract":"In this work, we report the growth of a single mixed Bi$_{1-x}$Sb$_x$ layer,\u0000with diverse stoichiometries, on a Ag(111) substrate. The atomic geometry has\u0000been thoroughly investigated by low energy electron diffraction, scanning\u0000tunneling microscopy, and X-ray photoelectron spectroscopy experiments, as well\u0000as calculations based on density functional theory (DFT). We first determined\u0000that both pure systems (Bi/Ag(111) and Sb/Ag(111)) show similar behaviors: they\u0000form surface alloys with ($sqrt{3}timessqrt{3}$)R30$^circ$ periodicity for\u0000coverages lower than 1/3 ML, and undergo a dealloying transition for higher\u0000coverages up to 2/3 ML. We then established a simple preparation procedure to\u0000obtain a mixed Bi-Sb overlayer on Ag(111): it is essential to start with a\u0000surface completely covered by either of the two pure surface alloys and then\u0000deposit the other element on it. The energetics derived from DFT calculations\u0000provide insight into the systems preference towards the formation of this\u0000phase, and also predict a pathway to the formation of Bi-rich non-alloyed\u0000phases. The obtained mixed Bi-Sb phase has a lateral atomic arrangement very\u0000similar to the one in the non-alloyed phase observed for Sb on Ag(111), with Sb\u0000and Bi atoms distributed disorderly, and presents a significant vertical\u0000corrugation, promising considerable Rashba effects.","PeriodicalId":501211,"journal":{"name":"arXiv - PHYS - Other Condensed Matter","volume":"233 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140299903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Martínez, P. A. Orellana, L. Rosales, J. Dolado, M. Amado, E. Diez, F. Domínguez-Adame, R. P. A. Lima
Bound states in the continuum (BICs) are exotic, localized states even though their energy lies in the continuum spectra. Since its discovery in 1929, the quest to unveil these exotic states in charge transport experiments remains an active pursuit in condensed matter physics. Here, we study charge transport in InSb nanowire networks in the ballistic regime and subject to a perpendicular magnetic field as ideal candidates to observe and control the appearance of BICs. We find that BICs reveal themselves as distinctive resonances or antiresonances in the conductance by varying the applied magnetic field and the Fermi energy. We systematically consider different lead connections in hashtag-like nanowire networks, finding the optimal configuration that enhances the features associated with the emergence of BICs. Finally, the investigation focuses on the effect of the Rashba spin-orbit interaction of InSb on the occurrence of BICs in nanowire networks. While the interaction generally plays a detrimental role in the signatures of the BICs in the conductance of the nanowire networks, it opens the possibility to operate these nanostructures as spin filters for spintronics. We believe that this work could pave the way for the unambiguous observation of BICs in charge transport experiments and for the development of advanced spintronic devices.
{"title":"Uncovering Bound States in the Continuum in InSb nanowire networks","authors":"D. Martínez, P. A. Orellana, L. Rosales, J. Dolado, M. Amado, E. Diez, F. Domínguez-Adame, R. P. A. Lima","doi":"arxiv-2403.15070","DOIUrl":"https://doi.org/arxiv-2403.15070","url":null,"abstract":"Bound states in the continuum (BICs) are exotic, localized states even though\u0000their energy lies in the continuum spectra. Since its discovery in 1929, the\u0000quest to unveil these exotic states in charge transport experiments remains an\u0000active pursuit in condensed matter physics. Here, we study charge transport in\u0000InSb nanowire networks in the ballistic regime and subject to a perpendicular\u0000magnetic field as ideal candidates to observe and control the appearance of\u0000BICs. We find that BICs reveal themselves as distinctive resonances or\u0000antiresonances in the conductance by varying the applied magnetic field and the\u0000Fermi energy. We systematically consider different lead connections in\u0000hashtag-like nanowire networks, finding the optimal configuration that enhances\u0000the features associated with the emergence of BICs. Finally, the investigation\u0000focuses on the effect of the Rashba spin-orbit interaction of InSb on the\u0000occurrence of BICs in nanowire networks. While the interaction generally plays\u0000a detrimental role in the signatures of the BICs in the conductance of the\u0000nanowire networks, it opens the possibility to operate these nanostructures as\u0000spin filters for spintronics. We believe that this work could pave the way for\u0000the unambiguous observation of BICs in charge transport experiments and for the\u0000development of advanced spintronic devices.","PeriodicalId":501211,"journal":{"name":"arXiv - PHYS - Other Condensed Matter","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140300035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pavel Stishenko, Adam McSloy, Berk Onat, Ben Hourahine, Reinhard J. Maurer, James R. Kermode, Andrew Logsdail
Modern software engineering of electronic structure codes has seen a paradigm shift from monolithic workflows towards object-based modularity. Software objectivity allows for greater flexibility in the application of electronic structure calculations, with particular benefits when integrated with approaches for data-driven analysis. Here, we discuss different approaches to create "deep" modular interfaces that connect big-data workflows and electronic structure codes, and explore the diversity of use cases that they can enable. We present two such interface approaches for the semi-empirical electronic structure package, DFTB+. In one case, DFTB+ is applied as a library and provides data to an external workflow; and in another, DFTB+ receives data via external bindings and processes the information subsequently within an internal workflow. We provide a general framework to enable data exchange workflows for embedding new machine-learning-based Hamiltonians within DFTB+, or to enabling deep integration of DFTB+ in multiscale embedding workflows. These modular interfaces demonstrate opportunities in emergent software and workflows to accelerate scientific discovery by harnessing existing software capabilities.
{"title":"Integrated workflows and interfaces for data-driven semi-empirical electronic structure calculations","authors":"Pavel Stishenko, Adam McSloy, Berk Onat, Ben Hourahine, Reinhard J. Maurer, James R. Kermode, Andrew Logsdail","doi":"arxiv-2403.15625","DOIUrl":"https://doi.org/arxiv-2403.15625","url":null,"abstract":"Modern software engineering of electronic structure codes has seen a paradigm\u0000shift from monolithic workflows towards object-based modularity. Software\u0000objectivity allows for greater flexibility in the application of electronic\u0000structure calculations, with particular benefits when integrated with\u0000approaches for data-driven analysis. Here, we discuss different approaches to\u0000create \"deep\" modular interfaces that connect big-data workflows and electronic\u0000structure codes, and explore the diversity of use cases that they can enable.\u0000We present two such interface approaches for the semi-empirical electronic\u0000structure package, DFTB+. In one case, DFTB+ is applied as a library and\u0000provides data to an external workflow; and in another, DFTB+ receives data via\u0000external bindings and processes the information subsequently within an internal\u0000workflow. We provide a general framework to enable data exchange workflows for\u0000embedding new machine-learning-based Hamiltonians within DFTB+, or to enabling\u0000deep integration of DFTB+ in multiscale embedding workflows. These modular\u0000interfaces demonstrate opportunities in emergent software and workflows to\u0000accelerate scientific discovery by harnessing existing software capabilities.","PeriodicalId":501211,"journal":{"name":"arXiv - PHYS - Other Condensed Matter","volume":"233 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140300018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fractal lattices, with their self-similar and intricate structures, offer potential platforms for engineering physical properties on the nanoscale and also for realizing and manipulating high order topological insulator states in novel ways. Here we present a theoretical discussion on localized corner and edge states, as well as electronic properties emerging from topological phases in Sierpinski Carpet within a $pi$-flux regime. A topological hopping parameter phase diagram is constructed from which different spatial localized states are identified following signatures of distinct fractal generations. The specific geometry and scaling properties of the fractal systems can guide the supported topological states types and their associated functionalities. A conductive device is proposed by coupling identical Sierpinski Carpet units providing transport response through projected edge states that carrier the details of the Sierpinski Carpet topology.
{"title":"Corner and Edge States in Topological Sierpinski Carpet Systems","authors":"L. L. Lage, N. C. Rappe, A. Latgé","doi":"arxiv-2403.13774","DOIUrl":"https://doi.org/arxiv-2403.13774","url":null,"abstract":"Fractal lattices, with their self-similar and intricate structures, offer\u0000potential platforms for engineering physical properties on the nanoscale and\u0000also for realizing and manipulating high order topological insulator states in\u0000novel ways. Here we present a theoretical discussion on localized corner and\u0000edge states, as well as electronic properties emerging from topological phases\u0000in Sierpinski Carpet within a $pi$-flux regime. A topological hopping\u0000parameter phase diagram is constructed from which different spatial localized\u0000states are identified following signatures of distinct fractal generations. The\u0000specific geometry and scaling properties of the fractal systems can guide the\u0000supported topological states types and their associated functionalities. A\u0000conductive device is proposed by coupling identical Sierpinski Carpet units\u0000providing transport response through projected edge states that carrier the\u0000details of the Sierpinski Carpet topology.","PeriodicalId":501211,"journal":{"name":"arXiv - PHYS - Other Condensed Matter","volume":"157 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The low-temperature properties of one and two layers of parahydrogen adsorbed on graphite are investigated theoretically through Quantum Monte Carlo simulations. We adopt a microscopic model that explicitly includes the corrugation of the substrate. We study the phase diagram of a monolayer up to second layer promotion, and the possible occurrence of superfluidity in the second layer. We obtain results down to a temperature as low as 8 mK. We find second-layer promotion to occur at a considerably greater coverage than obtained in previous calculations and estimated experimentally; moreover, we find no evidence of a possible finite superfluid response in the second layer, disproving recent theoretical predictions.
{"title":"Quantum Monte Carlo study of thin parahydrogen films on graphite","authors":"Jieru Hu, Massimo Boninsegni","doi":"arxiv-2403.12637","DOIUrl":"https://doi.org/arxiv-2403.12637","url":null,"abstract":"The low-temperature properties of one and two layers of parahydrogen adsorbed\u0000on graphite are investigated theoretically through Quantum Monte Carlo\u0000simulations. We adopt a microscopic model that explicitly includes the\u0000corrugation of the substrate. We study the phase diagram of a monolayer up to\u0000second layer promotion, and the possible occurrence of superfluidity in the\u0000second layer. We obtain results down to a temperature as low as 8 mK. We find\u0000second-layer promotion to occur at a considerably greater coverage than\u0000obtained in previous calculations and estimated experimentally; moreover, we\u0000find no evidence of a possible finite superfluid response in the second layer,\u0000disproving recent theoretical predictions.","PeriodicalId":501211,"journal":{"name":"arXiv - PHYS - Other Condensed Matter","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140172879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soumya Mukherjee, Anjan Kumar NM, Subhadip Manna, Sambhu G Nath, Radha Krishna Gopal, Chiranjib Mitra, N. Kamaraju
MnBi$_{2}$Te$_{4}$, the first topological insulator with inherent magnetic ordering, has attracted significant attention recently for providing a platform to realize several exotic quantum phenomena at relatively higher temperatures. In this work, we have carried out an exhaustive investigation of MnBi$_{2}$Te$_{4}$ and Sb doped MnBi$_{2}$Te$_{4}$ thin films using THz time-domain spectroscopy. The extracted real THz conductivity displays a strong IR active E$_u$ phonon absorption peak (at $sim$1.5 THz) merged on top of the Drude-like contributions from bulk and surface electrons. The extracted parameters from the THz conductivity data fitted to the Drude-Fano-Lorentz model, show significant changes in their temperature dependence around the magnetic ordering N'eel temperature of $sim$ 25K, which is suggestive of the coupling between magnetic ordering and electronic band structure. The frequency of the E$_u$ phonon displays an anomalous blue-shift with increasing temperatures by $sim$ 0.1 THz ($sim$7 %) for MnBi$_{2}$Te$_{4}$ and $sim$0.2 THz ($sim$13 %) for Sb doped MnBi$_{2}$Te$_{4}$ between 7K and 250K. The line-shape of the E$_u$ phonon mode in Sb doped MnBi$_{2}$Te$_{4}$ shows significant Fano asymmetry compared to that of MnBi$_{2}$Te$_{4}$, indicating that Sb doping plays an important role in the Fano interference between the phonons and the electrons, in this system. These results indicate that the anomalous phonon behaviour seen in MBT arise mainly from positive cubic anharmonicity induced self energy parameter, whereas both anharmonicity and the electron phonon coupling are at play in making the relatively higher anomalous blue shift of phonons in MBST. Our studies provide the first comprehensive understanding of the phonon and electron dynamics of MnBi$_{2}$Te$_{4}$ and Sb doped MnBi$_{2}$Te$_{4}$ in the THz range using time-domain THz spectroscopy.
{"title":"Investigation of magnetic order influenced phonon and electron dynamics in MnBi$_{2}$Te$_{4}$ and Sb doped MnBi$_{2}$Te$_{4}$ through terahertz time-domain spectroscopy","authors":"Soumya Mukherjee, Anjan Kumar NM, Subhadip Manna, Sambhu G Nath, Radha Krishna Gopal, Chiranjib Mitra, N. Kamaraju","doi":"arxiv-2403.11580","DOIUrl":"https://doi.org/arxiv-2403.11580","url":null,"abstract":"MnBi$_{2}$Te$_{4}$, the first topological insulator with inherent magnetic\u0000ordering, has attracted significant attention recently for providing a platform\u0000to realize several exotic quantum phenomena at relatively higher temperatures.\u0000In this work, we have carried out an exhaustive investigation of\u0000MnBi$_{2}$Te$_{4}$ and Sb doped MnBi$_{2}$Te$_{4}$ thin films using THz\u0000time-domain spectroscopy. The extracted real THz conductivity displays a strong\u0000IR active E$_u$ phonon absorption peak (at $sim$1.5 THz) merged on top of the\u0000Drude-like contributions from bulk and surface electrons. The extracted\u0000parameters from the THz conductivity data fitted to the Drude-Fano-Lorentz\u0000model, show significant changes in their temperature dependence around the\u0000magnetic ordering N'eel temperature of $sim$ 25K, which is suggestive of the\u0000coupling between magnetic ordering and electronic band structure. The frequency\u0000of the E$_u$ phonon displays an anomalous blue-shift with increasing\u0000temperatures by $sim$ 0.1 THz ($sim$7 %) for MnBi$_{2}$Te$_{4}$ and $sim$0.2\u0000THz ($sim$13 %) for Sb doped MnBi$_{2}$Te$_{4}$ between 7K and 250K. The\u0000line-shape of the E$_u$ phonon mode in Sb doped MnBi$_{2}$Te$_{4}$ shows\u0000significant Fano asymmetry compared to that of MnBi$_{2}$Te$_{4}$, indicating\u0000that Sb doping plays an important role in the Fano interference between the\u0000phonons and the electrons, in this system. These results indicate that the\u0000anomalous phonon behaviour seen in MBT arise mainly from positive cubic\u0000anharmonicity induced self energy parameter, whereas both anharmonicity and the\u0000electron phonon coupling are at play in making the relatively higher anomalous\u0000blue shift of phonons in MBST. Our studies provide the first comprehensive\u0000understanding of the phonon and electron dynamics of MnBi$_{2}$Te$_{4}$ and Sb\u0000doped MnBi$_{2}$Te$_{4}$ in the THz range using time-domain THz spectroscopy.","PeriodicalId":501211,"journal":{"name":"arXiv - PHYS - Other Condensed Matter","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. I. Klimovskikh, S. V. Eremeev, D. A. Estyunin, S. O. Filnov, K. Shimada, V. A. Golyashov, O. E. Tereshchenko, K. A. Kokh, A. S. Frolov, A. I. Sergeev, V. S. Stolyarov, V. Miksic Trontl, L. Petaccia, G. Di Santo, M. Tallarida, J. Dai, S. Blanco-Canosa, T. Valla, A. M. Shikin, E. V. Chulkov
Meeting of non-trivial topology with magnetism results in novel phases of matter, such as Quantum Anomalous Hall (QAH) or axion insulator phases. Even more exotic states with high and tunable Chern numbers are expected at the contact of intrinsic magnetic topological insulators (IMTIs) and 2D topological insulators (TIs).Here we synthesize a heterostructures composed of 2D TI and 3D IMTIs, specifically of bismuth bilayer on top of MnBi$_2$Te$_4$-family of compounds and study their electronic properties by means of angle-resolved photoelectron spectroscopy (ARPES) and density functional theory (DFT). The epitaxial interface is characterized by hybridized Bi and IMTI electronic states. The Bi bilayer-derived states on different members of MnBi$_2$Te$_4$-family of materials are similar, except in the region of mixing with the topological surface states of the substrate. In that region, the new, substrate dependent interface Dirac state is observed. Our emph{ab initio} calculations show rich interface phases with emergence of exchange split 1D edge states, making the Bi/IMTI heterostructures promising playground for observation of novel members in the family of quantum Hall effects.
{"title":"Interfacing Quantum Spin Hall and Quantum Anomalous Hall insulators: Bi bilayer on MnBi$_2$Te$_4$-family materials","authors":"I. I. Klimovskikh, S. V. Eremeev, D. A. Estyunin, S. O. Filnov, K. Shimada, V. A. Golyashov, O. E. Tereshchenko, K. A. Kokh, A. S. Frolov, A. I. Sergeev, V. S. Stolyarov, V. Miksic Trontl, L. Petaccia, G. Di Santo, M. Tallarida, J. Dai, S. Blanco-Canosa, T. Valla, A. M. Shikin, E. V. Chulkov","doi":"arxiv-2403.12287","DOIUrl":"https://doi.org/arxiv-2403.12287","url":null,"abstract":"Meeting of non-trivial topology with magnetism results in novel phases of\u0000matter, such as Quantum Anomalous Hall (QAH) or axion insulator phases. Even\u0000more exotic states with high and tunable Chern numbers are expected at the\u0000contact of intrinsic magnetic topological insulators (IMTIs) and 2D topological\u0000insulators (TIs).Here we synthesize a heterostructures composed of 2D TI and 3D\u0000IMTIs, specifically of bismuth bilayer on top of MnBi$_2$Te$_4$-family of\u0000compounds and study their electronic properties by means of angle-resolved\u0000photoelectron spectroscopy (ARPES) and density functional theory (DFT). The\u0000epitaxial interface is characterized by hybridized Bi and IMTI electronic\u0000states. The Bi bilayer-derived states on different members of\u0000MnBi$_2$Te$_4$-family of materials are similar, except in the region of mixing\u0000with the topological surface states of the substrate. In that region, the new,\u0000substrate dependent interface Dirac state is observed. Our emph{ab initio}\u0000calculations show rich interface phases with emergence of exchange split 1D\u0000edge states, making the Bi/IMTI heterostructures promising playground for\u0000observation of novel members in the family of quantum Hall effects.","PeriodicalId":501211,"journal":{"name":"arXiv - PHYS - Other Condensed Matter","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The realization of Haldane's topological graphene model in practical materials has presented significant challenges. Here, we propose achieving this model by embedding graphene in chiral cavities, using the asymptotically decoupled framework detailed in Ref. [Phys. Rev. Lett. 126, 153603 (2021)]. Additionally, we introduce an equilibrium strategy for achieving valley polarization in this system with C2-symmetry breaking. Through numerical methods, we quantify the locking of photon numbers with Bloch electrons and calculate the topology-induced imbalance of valley photons. Furthermore, we elucidate that topological phase transition is characterized by the sign change of photon numbers during interband excitation. These findings underscore the remarkable potential of utilizing cavity quantum fluctuations to engineer electronic and photonic properties specific to valleys and topologies, particularly within the realm of strong light-matter coupling.
在实际材料中实现霍尔丹的拓扑石墨烯模型面临着巨大挑战。在此，我们建议利用参考文献[Phys. Rev. Lett 126, 153603 (2021)]中详述的渐近解耦框架，通过将石墨烯嵌入手性空腔来实现这一模型。[此外，我们还介绍了一种在该系统中实现谷极化的平衡策略，并打破了 C2 对称性。通过数值方法，我们量化了光子数量与布洛赫电子的锁定，并计算了拓扑引起的谷光子失衡。此外，我们还阐明了拓扑相变的特征是带间激发时光子数的符号变化。这些发现凸显了利用空腔量子波动来设计特定于山谷和拓扑的电子和光子特性的巨大潜力，尤其是在强光-物质耦合领域。
{"title":"Emergent Haldane Model and Photon-Valley Locking in Chiral Cavities","authors":"Liu Yang, Qing-Dong Jiang","doi":"arxiv-2403.11063","DOIUrl":"https://doi.org/arxiv-2403.11063","url":null,"abstract":"The realization of Haldane's topological graphene model in practical\u0000materials has presented significant challenges. Here, we propose achieving this\u0000model by embedding graphene in chiral cavities, using the asymptotically\u0000decoupled framework detailed in Ref. [Phys. Rev. Lett. 126, 153603 (2021)].\u0000Additionally, we introduce an equilibrium strategy for achieving valley\u0000polarization in this system with C2-symmetry breaking. Through numerical\u0000methods, we quantify the locking of photon numbers with Bloch electrons and\u0000calculate the topology-induced imbalance of valley photons. Furthermore, we\u0000elucidate that topological phase transition is characterized by the sign change\u0000of photon numbers during interband excitation. These findings underscore the\u0000remarkable potential of utilizing cavity quantum fluctuations to engineer\u0000electronic and photonic properties specific to valleys and topologies,\u0000particularly within the realm of strong light-matter coupling.","PeriodicalId":501211,"journal":{"name":"arXiv - PHYS - Other Condensed Matter","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dylan Jones, Marcin Mucha-Kruczynski, Adelina Ilie, Lucian Covaci
The Lieb lattice is one of the simplest lattices that exhibits both linear Dirac-like and flat topological electronic bands. We propose to further tailor its electronic properties through periodic 1D electrostatic superlattices (SLs), which, in the long wavelength limit, were predicted to give rise to novel transport signatures, such as the omnidirectional super-Klein tunnelling (SKT). By numerically modelling the electronic structure at tight-binding level, we uncover the evolution of the Lieb SL band structure from the discrete all the way to the continuum regime and build a comprehensive picture of the Lieb lattice under 1D potentials. This approach allows us to also take into consideration the discrete lattice symmetry-breaking that occurs at the well/barrier interfaces created by the 1D SL, whose consequences cannot be explored using the previous low energy and long wavelength approaches. We find novel features in the band structure, among which are intersections of quadratic and flat bands, tilted Dirac cones, or series of additional anisotropic Dirac cones at energies where the SKT is predicted. Such features are relevant to experimental realizations of electronic transport in Lieb 1D SL realized in artificial lattices or in real material systems like 2D covalent organic/metal-organic frameworks and inorganic 2D solids.
{"title":"One-dimensional Lieb superlattices: from the discrete to the continuum limit","authors":"Dylan Jones, Marcin Mucha-Kruczynski, Adelina Ilie, Lucian Covaci","doi":"arxiv-2403.10382","DOIUrl":"https://doi.org/arxiv-2403.10382","url":null,"abstract":"The Lieb lattice is one of the simplest lattices that exhibits both linear\u0000Dirac-like and flat topological electronic bands. We propose to further tailor\u0000its electronic properties through periodic 1D electrostatic superlattices\u0000(SLs), which, in the long wavelength limit, were predicted to give rise to\u0000novel transport signatures, such as the omnidirectional super-Klein tunnelling\u0000(SKT). By numerically modelling the electronic structure at tight-binding\u0000level, we uncover the evolution of the Lieb SL band structure from the discrete\u0000all the way to the continuum regime and build a comprehensive picture of the\u0000Lieb lattice under 1D potentials. This approach allows us to also take into\u0000consideration the discrete lattice symmetry-breaking that occurs at the\u0000well/barrier interfaces created by the 1D SL, whose consequences cannot be\u0000explored using the previous low energy and long wavelength approaches. We find\u0000novel features in the band structure, among which are intersections of\u0000quadratic and flat bands, tilted Dirac cones, or series of additional\u0000anisotropic Dirac cones at energies where the SKT is predicted. Such features\u0000are relevant to experimental realizations of electronic transport in Lieb 1D SL\u0000realized in artificial lattices or in real material systems like 2D covalent\u0000organic/metal-organic frameworks and inorganic 2D solids.","PeriodicalId":501211,"journal":{"name":"arXiv - PHYS - Other Condensed Matter","volume":"129 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140147951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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