In order to promote the development of the next generation of nano-spintronic devices, it is of great significance to tune the freedom of valley in two-dimensional (2D) materials. Here, we propose a mechanism for manipulating the valley and nonlinear Hall effect by the 2D ferroelectric substrate. The monolayer Mn2P2S3Se3 is a robust antiferromagnetic valley polarized semiconductor. Importantly, the valley polarized metal-semiconductor phase transition of Mn2P2S3Se3 can be effectively tuned by switching the ferroelectric polarization of Sc2CO2. We reveal the microscopic mechanism of phase transition, which origins from the charge transfer and band alignment. Additionally, we find that transformed polarization direction of Sc2CO2 flexibly manipulate the Berry curvature dipole. Based on this discovery, we present the detection valley polarized metal-semiconductor transition by the nonlinear Hall effect devices. These findings not only offer a scheme to tune the valley degree of freedom, but also provide promising platform to design the nonlinear Hall effect devices.
{"title":"Ferroelectric tuning of the valley polarized metal-semiconductor transition in Mn2P2S3Se3/Sc2CO2 van der Waals heterostructures and application to nonlinear Hall effect devices","authors":"Hanbo Sun, Yewei Ren, Chao Wu, Pengqiang Dong, Weixi Zhang, Yin-Zhong Wu, Ping Li","doi":"arxiv-2409.06181","DOIUrl":"https://doi.org/arxiv-2409.06181","url":null,"abstract":"In order to promote the development of the next generation of nano-spintronic\u0000devices, it is of great significance to tune the freedom of valley in\u0000two-dimensional (2D) materials. Here, we propose a mechanism for manipulating\u0000the valley and nonlinear Hall effect by the 2D ferroelectric substrate. The\u0000monolayer Mn2P2S3Se3 is a robust antiferromagnetic valley polarized\u0000semiconductor. Importantly, the valley polarized metal-semiconductor phase\u0000transition of Mn2P2S3Se3 can be effectively tuned by switching the\u0000ferroelectric polarization of Sc2CO2. We reveal the microscopic mechanism of\u0000phase transition, which origins from the charge transfer and band alignment.\u0000Additionally, we find that transformed polarization direction of Sc2CO2\u0000flexibly manipulate the Berry curvature dipole. Based on this discovery, we\u0000present the detection valley polarized metal-semiconductor transition by the\u0000nonlinear Hall effect devices. These findings not only offer a scheme to tune\u0000the valley degree of freedom, but also provide promising platform to design the\u0000nonlinear Hall effect devices.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226284","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}
Taking into account some results obtained within the framework of non-equilibrium thermodynamics with internal variables (NET-IV) in a previous paper, where generalized Guyer-Krumhansl evolution equations for the heat flux in heat rigid conductors were derived, in this paper we obtain a heat transport equation describing conductive, viscous and vortical motions of phonons. To do so, we take as independent variables the internal energy, the heat flux, and a tensorial internal variable, with a symmetric part and an antisymmetric part, which turns out to be related to the rotational terms in the final equation. Besides the shear phonon viscosity arising in usual phonon hydrodynamics, we propose a rotational phonon viscosity, which would describe a transfer from ordered rotational motion of phonon vortices to rotational microscopic motions of diatomic particles constituting complex polar crystals, in analogy to the hydrodynamics of classical micropolar fluids. This possibility emphasizes the interest of exploring the interactions between the average heat flow and the heat vortices found in some models of phonon hydrodynamics.
{"title":"Internal tensorial variables and a heat transport equation with inertial, thermal viscosity and vorticity terms","authors":"Liliana Restuccia, David Jou, Michal Pavelka","doi":"arxiv-2409.06380","DOIUrl":"https://doi.org/arxiv-2409.06380","url":null,"abstract":"Taking into account some results obtained within the framework of\u0000non-equilibrium thermodynamics with internal variables (NET-IV) in a previous\u0000paper, where generalized Guyer-Krumhansl evolution equations for the heat flux\u0000in heat rigid conductors were derived, in this paper we obtain a heat transport\u0000equation describing conductive, viscous and vortical motions of phonons. To do\u0000so, we take as independent variables the internal energy, the heat flux, and a\u0000tensorial internal variable, with a symmetric part and an antisymmetric part,\u0000which turns out to be related to the rotational terms in the final equation.\u0000Besides the shear phonon viscosity arising in usual phonon hydrodynamics, we\u0000propose a rotational phonon viscosity, which would describe a transfer from\u0000ordered rotational motion of phonon vortices to rotational microscopic motions\u0000of diatomic particles constituting complex polar crystals, in analogy to the\u0000hydrodynamics of classical micropolar fluids. This possibility emphasizes the\u0000interest of exploring the interactions between the average heat flow and the\u0000heat vortices found in some models of phonon hydrodynamics.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"406 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206763","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}
Rafi Ud Din, Yuncheng Zhou, Reza Asgari, Gao Xianlong
We derive the general Fresnel coefficients for reflection by incorporating the Fizeau drag effect in doped graphene, which arises from the unique behavior of its massless Dirac electrons. Using the standard Maxwell equations and constitutive relations, we analyze the influence of this relativistic phenomenon on the optical properties of doped graphene. Our study focuses on the angular shift of Brewster's angle in a structure where monolayer graphene is sandwiched between two static dielectric media. Our findings reveal that the presence of the Fizeau drag effect significantly enhances the Brewster angle shift, leading to substantial modifications in the optical characteristics of the graphene channel, including notable alterations in the reflectance spectrum. We demonstrate that this angular shift can be further amplified by increasing the drift velocities and charge densities of the electrons in graphene, offering a tunable mechanism for controlling optical behavior in graphene-based systems. The findings of this work have significant implications for the design and development of planar photonic devices that take advantage of the optical characteristics of graphene. This breakthrough creates new opportunities for the use of graphene in sophisticated photonic technologies, where exact control over the interactions between light and matter is essential.
{"title":"Enhanced Brewster Angle Shift in Doped Graphene via the Fizeau Drag Effect","authors":"Rafi Ud Din, Yuncheng Zhou, Reza Asgari, Gao Xianlong","doi":"arxiv-2409.06467","DOIUrl":"https://doi.org/arxiv-2409.06467","url":null,"abstract":"We derive the general Fresnel coefficients for reflection by incorporating\u0000the Fizeau drag effect in doped graphene, which arises from the unique behavior\u0000of its massless Dirac electrons. Using the standard Maxwell equations and\u0000constitutive relations, we analyze the influence of this relativistic\u0000phenomenon on the optical properties of doped graphene. Our study focuses on\u0000the angular shift of Brewster's angle in a structure where monolayer graphene\u0000is sandwiched between two static dielectric media. Our findings reveal that the\u0000presence of the Fizeau drag effect significantly enhances the Brewster angle\u0000shift, leading to substantial modifications in the optical characteristics of\u0000the graphene channel, including notable alterations in the reflectance\u0000spectrum. We demonstrate that this angular shift can be further amplified by\u0000increasing the drift velocities and charge densities of the electrons in\u0000graphene, offering a tunable mechanism for controlling optical behavior in\u0000graphene-based systems. The findings of this work have significant implications\u0000for the design and development of planar photonic devices that take advantage\u0000of the optical characteristics of graphene. This breakthrough creates new\u0000opportunities for the use of graphene in sophisticated photonic technologies,\u0000where exact control over the interactions between light and matter is\u0000essential.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206725","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}
We demonstrate that two-dimensional Kramers-Weyl fermions can be engineered in spin-orbit coupled twisted bilayers, where the chiral structure of these moir'e systems breaks all mirror symmetries, confining Kramers-Weyl fermions to high-symmetry points in the Brillouin zone under time reversal symmetry. Our theoretical analysis reveals a symmetry-enforced Weyl-like interlayer moir'e coupling that universally ensures an ideal radial spin-texture at arbitrary twist angles, under $C_{nz}$ symmetry with n>2. First principles density functional calculation confirm the realization of these fermions in twisted $alpha$-In$_2$Se$_3$ bilayers, where flat bands and out-of-plane ferroelectric polarization in each layer guarantee two-dimensional Kramers-Weyl physics with perfectly ideal radial spin textures.
{"title":"Moiré Kramers-Weyl Fermions from Structural Chirality with Ideal Radial Spin Texture","authors":"D. J. P. de Sousa, Seungjun Lee, Tony Low","doi":"arxiv-2409.06806","DOIUrl":"https://doi.org/arxiv-2409.06806","url":null,"abstract":"We demonstrate that two-dimensional Kramers-Weyl fermions can be engineered\u0000in spin-orbit coupled twisted bilayers, where the chiral structure of these\u0000moir'e systems breaks all mirror symmetries, confining Kramers-Weyl fermions\u0000to high-symmetry points in the Brillouin zone under time reversal symmetry. Our\u0000theoretical analysis reveals a symmetry-enforced Weyl-like interlayer moir'e\u0000coupling that universally ensures an ideal radial spin-texture at arbitrary\u0000twist angles, under $C_{nz}$ symmetry with n>2. First principles density\u0000functional calculation confirm the realization of these fermions in twisted\u0000$alpha$-In$_2$Se$_3$ bilayers, where flat bands and out-of-plane ferroelectric\u0000polarization in each layer guarantee two-dimensional Kramers-Weyl physics with\u0000perfectly ideal radial spin textures.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206723","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 voltage is a sensitive quantity to quantum interference in coherent electronic transport. We study the voltage fluctuations in disordered graphene nanoribbons with zigzag and armchair edge terminations in a four-terminal configuration. We show that the average and standard deviation of the voltage oscillates with the separation of the attached voltage probes and depend on the coupling strength of the probes. The voltage fluctuations can be large enough to observe negative voltages for weakly coupled probes. As we numerically verified, the voltage fluctuations are described within a random matrix approach for weakly disordered nanoribbons at energies away from the Fermi energy. However, near the Fermi energy, zigzag nanoribbons exhibit Anderson localization, whereas electrons are anomalously localized in armchair nanoribbons. This distinction leads to different voltage statistics for zigzag and armchair nanoribbons.
{"title":"Four-terminal voltage fluctuations in disordered graphene nanoribbons: Anderson and anomalous localization effects","authors":"Pablo Encarnación, Victor A. Gopar","doi":"arxiv-2409.06891","DOIUrl":"https://doi.org/arxiv-2409.06891","url":null,"abstract":"The voltage is a sensitive quantity to quantum interference in coherent\u0000electronic transport. We study the voltage fluctuations in disordered graphene\u0000nanoribbons with zigzag and armchair edge terminations in a four-terminal\u0000configuration. We show that the average and standard deviation of the voltage\u0000oscillates with the separation of the attached voltage probes and depend on the\u0000coupling strength of the probes. The voltage fluctuations can be large enough\u0000to observe negative voltages for weakly coupled probes. As we numerically\u0000verified, the voltage fluctuations are described within a random matrix\u0000approach for weakly disordered nanoribbons at energies away from the Fermi\u0000energy. However, near the Fermi energy, zigzag nanoribbons exhibit Anderson\u0000localization, whereas electrons are anomalously localized in armchair\u0000nanoribbons. This distinction leads to different voltage statistics for zigzag\u0000and armchair nanoribbons.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206721","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}
We investigate the efficiency of charge-to-spin conversion in two-dimensional Rashba altermagnets, a class of materials that merge characteristics of both ferromagnets and antiferromagnets. Utilizing quantum linear response theory, we quantify the longitudinal and spin Hall conductivities in this system and demonstrate that a substantial enhancement of the spin Hall angle is achieved below the band crossing point through the dual effects of relativistic spin-orbit interaction and nonrelativistic altermagnetic exchange interaction. Additionally, we find that skew scattering and topology-related intrinsic mechanisms are almost negligible in this system, which contrasts with conventional ferromagnetic Rashba systems. Our findings not only advance the understanding of spin dynamics in Rashba altermagnets but also pave the way for novel strategies in manipulating charge-to-spin conversion via the sophisticated control of noncollinear in-plane and collinear out-of-plane spin textures.
{"title":"Helicity controlled spin Hall angle in the 2D Rashba altermagnets","authors":"Weiwei Chen, Longhai Zeng, W. Zhu","doi":"arxiv-2409.06167","DOIUrl":"https://doi.org/arxiv-2409.06167","url":null,"abstract":"We investigate the efficiency of charge-to-spin conversion in two-dimensional\u0000Rashba altermagnets, a class of materials that merge characteristics of both\u0000ferromagnets and antiferromagnets. Utilizing quantum linear response theory, we\u0000quantify the longitudinal and spin Hall conductivities in this system and\u0000demonstrate that a substantial enhancement of the spin Hall angle is achieved\u0000below the band crossing point through the dual effects of relativistic\u0000spin-orbit interaction and nonrelativistic altermagnetic exchange interaction.\u0000Additionally, we find that skew scattering and topology-related intrinsic\u0000mechanisms are almost negligible in this system, which contrasts with\u0000conventional ferromagnetic Rashba systems. Our findings not only advance the\u0000understanding of spin dynamics in Rashba altermagnets but also pave the way for\u0000novel strategies in manipulating charge-to-spin conversion via the\u0000sophisticated control of noncollinear in-plane and collinear out-of-plane spin\u0000textures.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206766","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}
Abdullah S. Abbas, Daniel Chabeda, Daniel Weinberg, David T. Limmer, Eran Rabani, A. Paul Alivisatos
Lead-halide perovskite nanocrystals have recently emerged as desirable optical materials for applications such as coherent quantum light emitters and solid-state laser cooling due to their short radiative lifetime and near-unity photoluminescence quantum yield. Here, we investigate the effect of CsPbBr3 nanocrystal size on the radiative lifetime under ambient conditions. High-quality nanocrystals, with monoexponential time-resolved photoluminescence decay behaviors, unveil a non-monotonic trend in radiative lifetime. This non-monotonicity appears to reflect a behavior common among II-VI (CdSe) and perovskites semiconducting nanocrystals. We find that large nanocrystals in the weak quantum confinement regime exhibit long radiative lifetimes due to a thermally accessible population of dim states. Small nanocrystals within the strong quantum confinement regime, surprisingly, also show long radiative lifetimes, due however to a substantial reduction in oscillator strength. Nanocrystals in the intermediate quantum confinement regime displays the shortest radiative lifetime, as their oscillator strength is enhanced relative to particles in the strong confinement regime, but do not have sufficient low-lying dim states like the large particles to counteract this affect. These findings shed light on the impact of nanocrystal size on radiative lifetime and pave the way for tailored optical materials in various optical applications.
{"title":"Non-Monotonic Size-Dependent Exciton Radiative Lifetime in CsPbBr3 Nanocrystals","authors":"Abdullah S. Abbas, Daniel Chabeda, Daniel Weinberg, David T. Limmer, Eran Rabani, A. Paul Alivisatos","doi":"arxiv-2409.06165","DOIUrl":"https://doi.org/arxiv-2409.06165","url":null,"abstract":"Lead-halide perovskite nanocrystals have recently emerged as desirable\u0000optical materials for applications such as coherent quantum light emitters and\u0000solid-state laser cooling due to their short radiative lifetime and near-unity\u0000photoluminescence quantum yield. Here, we investigate the effect of CsPbBr3\u0000nanocrystal size on the radiative lifetime under ambient conditions.\u0000High-quality nanocrystals, with monoexponential time-resolved photoluminescence\u0000decay behaviors, unveil a non-monotonic trend in radiative lifetime. This\u0000non-monotonicity appears to reflect a behavior common among II-VI (CdSe) and\u0000perovskites semiconducting nanocrystals. We find that large nanocrystals in the\u0000weak quantum confinement regime exhibit long radiative lifetimes due to a\u0000thermally accessible population of dim states. Small nanocrystals within the\u0000strong quantum confinement regime, surprisingly, also show long radiative\u0000lifetimes, due however to a substantial reduction in oscillator strength.\u0000Nanocrystals in the intermediate quantum confinement regime displays the\u0000shortest radiative lifetime, as their oscillator strength is enhanced relative\u0000to particles in the strong confinement regime, but do not have sufficient\u0000low-lying dim states like the large particles to counteract this affect. These\u0000findings shed light on the impact of nanocrystal size on radiative lifetime and\u0000pave the way for tailored optical materials in various optical applications.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"175 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206769","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}
Elena Rozas, Yannik Brune, Ken West, Kirk W. Baldwin, Loren N. Pfeiffer, Jonathan Beaumariage, Hassan Alnatah, David W. Snoke, Marc Aßmann
In non-Hermitian open quantum systems, such as polariton condensates, local tailoring of gains and losses opens up an interesting possibility to realize functional optical elements. Here, we demonstrate that deliberately introducing losses via a photonic defect, realized by reducing the quality factor of a DBR mirror locally within an ultrahigh-quality microcavity, may be utilized to create directed polariton currents towards the defect. We discuss the role of polariton-polariton interactions in the process and how to tailor the effective decay time of a polariton condensate via coupling to the defect. Our results highlight the far-reaching potential of non-Hermitian physics in polaritonics.
{"title":"Targeted Polariton Flow Through Tailored Photonic Defects","authors":"Elena Rozas, Yannik Brune, Ken West, Kirk W. Baldwin, Loren N. Pfeiffer, Jonathan Beaumariage, Hassan Alnatah, David W. Snoke, Marc Aßmann","doi":"arxiv-2409.06478","DOIUrl":"https://doi.org/arxiv-2409.06478","url":null,"abstract":"In non-Hermitian open quantum systems, such as polariton condensates, local\u0000tailoring of gains and losses opens up an interesting possibility to realize\u0000functional optical elements. Here, we demonstrate that deliberately introducing\u0000losses via a photonic defect, realized by reducing the quality factor of a DBR\u0000mirror locally within an ultrahigh-quality microcavity, may be utilized to\u0000create directed polariton currents towards the defect. We discuss the role of\u0000polariton-polariton interactions in the process and how to tailor the effective\u0000decay time of a polariton condensate via coupling to the defect. Our results\u0000highlight the far-reaching potential of non-Hermitian physics in polaritonics.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206724","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}
Vanessa D. Kegler, Igor S. S. de Oliveira, Dominike Pacine, Teldo A. S. Pereira, Ricardo W. Nunes, Erika N. Lima
This study investigates the structural, mechanical, and electronic properties of novel two-dimensional (2D) pentaoctite (PO) monolayers composed of group-IV elements (PO-C, PO-Si, PO-Ge, and PO-Sn) using first-principles calculations. Stability is explored through phonon spectra and ab initio molecular dynamics simulations, confirming that all proposed structures are dynamically and thermally stable. Mechanical analysis shows that PO-C monolayers exhibit exceptional rigidity, while the others demonstrate greater flexibility, making them suitable for applications in foldable materials. The electronic properties show semimetallic behavior for PO-C and metallic behavior for PO-Si, while PO-Ge and PO-Sn possess narrow band gaps, positioning them as promising candidates for semiconductor applications. Additionally, PO-C exhibits potential as an efficient catalyst for the hydrogen evolution reaction (HER), with strain engineering further enhancing its catalytic performance. These findings suggest a wide range of technological applications, from nanoelectronics and nanomechanics to metal-free catalysis in sustainable energy production.
{"title":"Group-IV Pentaoctite: A New 2D Material Family","authors":"Vanessa D. Kegler, Igor S. S. de Oliveira, Dominike Pacine, Teldo A. S. Pereira, Ricardo W. Nunes, Erika N. Lima","doi":"arxiv-2409.05986","DOIUrl":"https://doi.org/arxiv-2409.05986","url":null,"abstract":"This study investigates the structural, mechanical, and electronic properties\u0000of novel two-dimensional (2D) pentaoctite (PO) monolayers composed of group-IV\u0000elements (PO-C, PO-Si, PO-Ge, and PO-Sn) using first-principles calculations.\u0000Stability is explored through phonon spectra and ab initio molecular dynamics\u0000simulations, confirming that all proposed structures are dynamically and\u0000thermally stable. Mechanical analysis shows that PO-C monolayers exhibit\u0000exceptional rigidity, while the others demonstrate greater flexibility, making\u0000them suitable for applications in foldable materials. The electronic properties\u0000show semimetallic behavior for PO-C and metallic behavior for PO-Si, while\u0000PO-Ge and PO-Sn possess narrow band gaps, positioning them as promising\u0000candidates for semiconductor applications. Additionally, PO-C exhibits\u0000potential as an efficient catalyst for the hydrogen evolution reaction (HER),\u0000with strain engineering further enhancing its catalytic performance. These\u0000findings suggest a wide range of technological applications, from\u0000nanoelectronics and nanomechanics to metal-free catalysis in sustainable energy\u0000production.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206767","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}
Topological qubits based on non-abelian Majorana bound states (MBSs) are protected by parity which is challenged by quasiparticle poisoning (QPP). In this work, we show how QPP affects transport through a pair of coupled MBSs weakly connected to two current leads, using an open system approach and full counting statistics. We find that the correct low-energy physics requires to include next to leading order tunneling events in the coupling to the leads. In particular, our results show that QPP causes super-Poissonian local shot noise with a Fano factor that diverges with decreasing bias voltage, while the current and the non-local (cross-)noise are only little affected. We explain that these features are a direct consequence of the nature of MBSs being their own antiparticle making noise measurements a viable tool to search for MBSs in the presence of QPP.
{"title":"Super-Poissonian noise from quasiparticle poisoning in electron transport through a pair of Majorana bound states","authors":"Florinda Viñas Boström, Patrik Recher","doi":"arxiv-2409.05594","DOIUrl":"https://doi.org/arxiv-2409.05594","url":null,"abstract":"Topological qubits based on non-abelian Majorana bound states (MBSs) are\u0000protected by parity which is challenged by quasiparticle poisoning (QPP). In\u0000this work, we show how QPP affects transport through a pair of coupled MBSs\u0000weakly connected to two current leads, using an open system approach and full\u0000counting statistics. We find that the correct low-energy physics requires to\u0000include next to leading order tunneling events in the coupling to the leads. In\u0000particular, our results show that QPP causes super-Poissonian local shot noise\u0000with a Fano factor that diverges with decreasing bias voltage, while the\u0000current and the non-local (cross-)noise are only little affected. We explain\u0000that these features are a direct consequence of the nature of MBSs being their\u0000own antiparticle making noise measurements a viable tool to search for MBSs in\u0000the presence of QPP.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206775","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：