{"title":"Three-dimensional valley-contrasting sound","authors":"Haoran Xue, Yong Ge, Zheyu Cheng, Yi-jun Guan, Jiaojiao Zhu, Hong-yu Zou, Shou-qi Yuan, Shengyuan A. Yang, Hong-xiang Sun, Yidong Chong, Baile Zhang","doi":"arxiv-2409.11714","DOIUrl":"https://doi.org/arxiv-2409.11714","url":null,"abstract":"Spin and valley are two fundamental properties of electrons in crystals. The\u0000similarity between them is well understood in valley-contrasting physics\u0000established decades ago in two-dimensional (2D) materials like graphene--with\u0000broken inversion symmetry, the two valleys in graphene exhibit opposite orbital\u0000magnetic moments, similar to the spin-1/2 behaviors of electrons, and opposite\u0000Berry curvature that leads to a half topological charge. However,\u0000valley-contrasting physics has never been explored in 3D crystals. Here, we\u0000develop a 3D acoustic crystal exhibiting 3D valley-contrasting physics. Unlike\u0000spin that is fundamentally binary, valley in 3D can take six different values,\u0000each carrying a vortex in a distinct direction. The topological valley\u0000transport is generalized from the edge states of 2D materials to the surface\u0000states of 3D materials, with interesting features including robust propagation,\u0000topological refraction, and valley-cavity localization. Our results open a new\u0000route for wave manipulation in 3D space.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253496","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}
{"title":"Interlayer dislocations in multilayer and bulk MoS${}_2$","authors":"Isaac Soltero, Vladimir I. Fal'ko","doi":"arxiv-2409.12030","DOIUrl":"https://doi.org/arxiv-2409.12030","url":null,"abstract":"Dislocations in van der Waals materials are linear defects confined to the\u0000interfaces between consecutive stoichiometric monolayers of a bulk layered\u0000crystal. Here, we present a mesoscale model for the description of interlayer\u0000dislocations in thin films of transition metal dichalcogenides. Taking\u00002H-MoS${}_2$ as a representative material, we compute the dependence of the\u0000dislocation energy on the film thickness, from few-layer MoS$_2$ to the bulk\u0000crystal, and analyse the strain field in the layers surrounding a dislocation.\u0000We also analyse the influence of strain field on the band edge profiles for\u0000electrons and holes, and conclude that the resulting energy profiles are\u0000incapable of localising charge carriers, in particular at room temperature.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253551","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}
Stefania De Palo, Saverio Moroni, Francesco Ancilotto, Pierluigi Silvestrelli, Luciano Reatto
{"title":"Borophane as substrate for adsorption of He-4: A journey across dimensionality","authors":"Stefania De Palo, Saverio Moroni, Francesco Ancilotto, Pierluigi Silvestrelli, Luciano Reatto","doi":"arxiv-2409.11913","DOIUrl":"https://doi.org/arxiv-2409.11913","url":null,"abstract":"In search of substrates for adsorption of He atoms allowing for novel quantum\u0000phases in restricted geometry we study the case of borophane. We focus on two\u0000allotropes of borophane, alpha-4H and Rect-2H. With a suitable Density\u0000Functional Theory we characterize the adsorption potential of a He atom on such\u0000crystalline substrates finding its corrugation, the preferential adsorption\u0000sites and the energy barrier between sites. Rect-2H borophane is particularly\u0000interesting due to thepresence of ridges in the adsorption potential with\u0000modest energy barriers in one direction of the basal plane and much higher\u0000barrier in the orthogonal direction, thus forming channels for motion of the\u0000adsorbed atoms. We study the adsorption of He-4 on Rect-2H borophane using Path\u0000Integral Monte Carlo simulations. In the first adsorbed layer the He-4 atoms\u0000are rather delocalized along a channel with no exchanges between channels. This\u0000strong anisotropy is present also in the first few additional adsorption layers\u0000of He-4 with presence of ordered and of disordered regions. In the second and\u0000the fifth layers at low temperature we find superfluidity on the length scale\u0000of the simulated systems. In the second layer the superfluidity is\u0000one-dimensional along the grooves. In the fifth layer the state is a strongly\u0000anisotropic two-dimensional superfluid at low coverage, with a crossover to an\u0000isotropic one at layer completion. Starting from the sixth layer the adsorbed\u0000He-4 film evolves toward a three-dimensional superfluid. Our main prediction is\u0000that Rect-2H borophane as a substrate will allow to probe 1D superfluidity in\u0000the second absorption layer, as well as the evolution from a 2D anisotropic\u0000superfluid to an isotropic one in the fifth layer, and eventually the onset of\u00003D superfluidity for higher coverages.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253494","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}
Longju Yu, Hong Jian Zhao, Yurong Yang, Laurent Bellaiche, Yanming Ma
{"title":"Anomalous Hall effect from nonlinear magnetoelectric coupling","authors":"Longju Yu, Hong Jian Zhao, Yurong Yang, Laurent Bellaiche, Yanming Ma","doi":"arxiv-2409.11662","DOIUrl":"https://doi.org/arxiv-2409.11662","url":null,"abstract":"The anomalous Hall effect (AHE) is a topology-related transport phenomenon\u0000being of potential interest in spintronics, because this effect enables the\u0000efficient probe of magnetic orders (i.e., data readout in memory devices). It\u0000is well known that AHE spontaneously occurs in ferromagnets or antiferromagnets\u0000with magnetization. While recent studies reveal electric-field induced AHE (via\u0000linear magnetoelectric coupling), an AHE originating from nonlinear\u0000magnetoelectric coupling remains largely unexplored. Here, by symmetry\u0000analysis, we establish the phenomenological theory regarding the spontaneous\u0000and electric-field driven AHE in magnets. We show that a large variety of\u0000magnetic point groups host an AHE that is driven by uni-axial, bi-axial, or\u0000tri-axial electric field and that comes from nonlinear magnetoelectric\u0000coupling. Such electric-field driven anomalous Hall conductivities are\u0000reversible by reversing the magnetic orders. Furthermore, our first-principles\u0000calculations suggest Cr2O3 and CoF2 as candidates hosting the aforementioned\u0000AHE. Our work emphasizes the important role of nonlinear magnetoelectric\u0000coupling in creating exotic transport phenomena, and offers alternative avenues\u0000for the probe of magnetic orders.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253547","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}
Marcelo Lopes Pereira, Jr, Emanuel J. A. dos Santos, Luiz Antonio Ribeiro, Jr, Douglas Soares Galvão
{"title":"How does Goldene Stack?","authors":"Marcelo Lopes Pereira, Jr, Emanuel J. A. dos Santos, Luiz Antonio Ribeiro, Jr, Douglas Soares Galvão","doi":"arxiv-2409.11880","DOIUrl":"https://doi.org/arxiv-2409.11880","url":null,"abstract":"The recent synthesis of Goldene, a 2D atomic monolayer of gold, has opened\u0000new avenues in exploring novel materials. However, the question of when\u0000multilayer Goldene transitions into bulk gold remains unresolved. This study\u0000used density functional theory calculations to address this fundamental\u0000question. Our findings reveal that multilayer Goldene retains an AA-like\u0000stacking configuration of up to six layers, with no observation of Bernal-like\u0000stacking as seen in graphene. Goldene spontaneously transitions to a bulk-like\u0000gold structure at seven layers, adopting a rhombohedral (ABC-like) stacking\u0000characteristic of bulk face-centered cubic (FCC) gold. The atomic arrangement\u0000converges entirely to the bulk gold lattice for more than ten layers. Quantum\u0000confinement significantly impacts the electronic properties, with monolayer and\u0000bulk Goldene exhibiting a single Dirac cone at the X-point of the Brillouin\u0000zone. In contrast, multilayer Goldene shows two Dirac cones at the X- and\u0000Y-points. Additionally, monolayer Goldene exhibits anisotropic optical\u0000absorption, which is absent in bulk gold. This study provides a deeper\u0000understanding of multilayer Goldene's structural and electronic properties and\u0000stacked 2D materials in general.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253500","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}
Sayan Sarkar, Sunit Das, Debottam Mandal, Amit Agarwal
{"title":"Light-induced Nonlinear Resonant Spin Magnetization","authors":"Sayan Sarkar, Sunit Das, Debottam Mandal, Amit Agarwal","doi":"arxiv-2409.12142","DOIUrl":"https://doi.org/arxiv-2409.12142","url":null,"abstract":"The optical generation of nonequilibrium spin magnetization plays a crucial\u0000role in advancing spintronics, providing ultrafast control of magnetization\u0000dynamics without the need for magnetic fields. Here, we demonstrate the\u0000feasibility of light-induced nonlinear spin magnetization (LNSM), which becomes\u0000a dominant effect in centrosymmetric materials. We reveal the quantum geometric\u0000origins of various LNSM contributions in both metallic and insulating systems.\u0000Through detailed symmetry analysis, we predict significant LNSM in the\u0000antiferromagnetic material CuMnAs. Notably, under circularly polarized light,\u0000the spin magnetization exhibits helicity-dependent behavior, reversing with\u0000opposite light helicity. These findings open up new possibilities for\u0000generating LNSM-driven nonlinear spin-orbit torques and developing innovative\u0000opto-spintronic devices.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253493","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}
Christian Marty, Zijin Lei, Saverio Silletta, Christian Reichl, Werner Dietsche, Werner Wegscheider
{"title":"Memory resistor based in GaAs 2D-bilayers: In and out of equilibrium","authors":"Christian Marty, Zijin Lei, Saverio Silletta, Christian Reichl, Werner Dietsche, Werner Wegscheider","doi":"arxiv-2409.11850","DOIUrl":"https://doi.org/arxiv-2409.11850","url":null,"abstract":"Resonant tunneling between closely spaced two dimensional electron gases is a\u0000single particle phenomenon that has sparked interest for decades. High\u0000tunneling conductances at equal electron densities are observed whenever the\u0000Fermi levels of the two quantum wells align. Detuning the Fermi levels out of\u0000the resonant 2D-2D tunneling regime causes a negative differential resistance.\u0000The negative differential resistance leads to a hysteresis when operating the\u0000device in a current driven mode, allowing a bilayer system to function as a\u0000volatile memory resistor.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253495","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}
{"title":"Moving skyrmions in Antiferromagnets by Sublattice Displacements","authors":"Michael Lau, Wolfgang Häusler, Michael Thorwart","doi":"arxiv-2409.11493","DOIUrl":"https://doi.org/arxiv-2409.11493","url":null,"abstract":"The texture in antiferromagnets hosting a topologically protected skyrmion\u0000can be viewed as two effectively coupled ferromagnetic skyrmions. Assuming\u0000rigid magnetic configurations, we show that this coupling results in an\u0000effective mass of the antiferromagnetic skyrmion and that its dynamics can be\u0000viewed as due to a relative displacement of the two sublattice ferromagnetic\u0000skyrmions. The theory holds for different antiferromagnetic systems and\u0000includes effects from dissipation and external forces caused by electric\u0000currents. We verify our analytical results by micromagnetic simulations.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253499","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}
{"title":"Phonon Thermal Transport between Two in-Plane, Two-Dimensional Nanoribbons in the Extreme Near-Field Regime","authors":"Md Jahid Hasan Sagor, Sheila Edalatpour","doi":"arxiv-2409.11345","DOIUrl":"https://doi.org/arxiv-2409.11345","url":null,"abstract":"The phonon thermal conductance of sub-nanometric vacuum gaps between two\u0000in-plane nanoribbons of two-dimensional materials (graphene and silicene) is\u0000analyzed using the atomistic Green's function method and by employing the\u0000Tersoff and Lennard-Jones potentials for describing the interatomic\u0000interactions. It is found that the phonon conductance decays exponentially with\u0000the size of the gap. Three exponential regimes have been identified. In the\u0000regime where the Lennard-Jones (L-J) potential is driven by the repulsive\u0000interatomic forces, caused by the overlap of electronic orbits, there is a\u0000sharp exponential decay in conductance as the gap increases (exp(-10.0d) for\u0000graphene). When both the repulsive and attractive (van der Waals) interatomic\u0000forces contribute to the L-J potential, the decay rate of the conductance\u0000significantly reduces to exp(-2.0d) for graphene and exp(-2.5d) for silicene.\u0000In the regime where attractive van der Waals forces dominate the L-J potential,\u0000phonon conductance has the slowest exponential decay as exp(-1.3d) for both\u0000silicene and graphene. It is also found that the contribution from the optical\u0000phonons to the conductance is non-negligible only for very small gaps between\u0000graphene nanoribbons (d < 1.6 AA). The phonon conductance of the gap is shown\u0000to vary with the width of the nanoribbon very modestly, such that the thermal\u0000conductivity of the gap linearly increases with the nanoribbon widths. The\u0000results of this study are of significance for fundamental understanding of heat\u0000transfer in the extreme near-field regime and for predicting the effect of\u0000interfaces and defects on heat transfer.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253548","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}
Carsten Speckmann, Andrea Angeletti, Lukáš Kývala, David Lamprecht, Felix Herterich, Clemens Mangler, Lado Filipovic, Christoph Dellago, Cesare Franchini, Jani Kotakoski
{"title":"Electron-beam-induced adatom-vacancy-complexes in mono- and bilayer phosphorene","authors":"Carsten Speckmann, Andrea Angeletti, Lukáš Kývala, David Lamprecht, Felix Herterich, Clemens Mangler, Lado Filipovic, Christoph Dellago, Cesare Franchini, Jani Kotakoski","doi":"arxiv-2409.11102","DOIUrl":"https://doi.org/arxiv-2409.11102","url":null,"abstract":"Phosphorene, a puckered two-dimensional allotrope of phosphorus, has sparked\u0000considerable interest in recent years due to its potential especially for\u0000optoelectronic applications with its layer-number-dependant direct band gap and\u0000strongly bound excitons. However, detailed experimental characterization of its\u0000intrinsic defects as well as its defect creation characteristics under electron\u0000irradiation are scarce. Here, we report on the creation and stability of a\u0000variety of defect configurations under 60 kV electron irradiation in mono- and\u0000bilayer phosphorene including the first experimental reports of stable\u0000adatom-vacancy-complexes. Displacement cross section measurements in bilayer\u0000phosphorene yield a value of 7.7 +- 1.4 barn with an estimated lifetime of\u0000adatom-vacancy-complexes of 19.9 +- 0.7 s, while some are stable for up to 68 s\u0000under continuous electron irradiation. Surprisingly, ab initio-based\u0000simulations indicate that the complexes should readily recombine, even in\u0000structures strained by up to 3 %. The presented results will help to improve\u0000the understanding of the wide variety of defects in phosphorene, their\u0000creation, and their stability, which may enable new pathways for defect\u0000engineered phosphorene devices.","PeriodicalId":501137,"journal":{"name":"arXiv - PHYS - Mesoscale and Nanoscale Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253550","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}