npj Quantum Materials最新文献_第5页

Coexistence and interplay of pseudomagnetism and flexoelectricity in few-layer rippled graphene 小层波纹石墨烯中伪磁性和挠性的共存与相互作用

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-12-19 DOI: 10.1038/s41535-024-00716-5

Jinrong Xu, Zhenyu Zhang, Ping Cui

{"title":"Coexistence and interplay of pseudomagnetism and flexoelectricity in few-layer rippled graphene","authors":"Jinrong Xu, Zhenyu Zhang, Ping Cui","doi":"10.1038/s41535-024-00716-5","DOIUrl":"https://doi.org/10.1038/s41535-024-00716-5","url":null,"abstract":"The mechanical strain has been widely exploited as an effective knob to induce various intriguing phenomena in two-dimensional materials, notably the emergence of pseudomagnetism and flexoelectricity. Here, using tight-binding model calculations supplemented with selective crosschecks within first-principles theory, we present the first demonstration of coexisting pseudo magnetism and flexoelectricity in both rippled graphene monolayer and bilayer and further reveal the interplay of the strain-induced phenomena. For a rippled monolayer, lattice distortion induces the emergence of a synchronously modulated pseudomagnetic field, which in turn breaks the charge neutrality of the sublattices, as manifested by the concomitant presence of in-plane flexoelectricity. For a rippled bilayer, pseudomagnetism substantially enhances in some regions of the bottom layer and disappears in the corresponding regions of the top layer due to pronounced interlayer coupling, or vice versa, accompanied by simultaneous in-plane and out-of-plane polarizations with opposite directions. Collectively, these findings offer new opportunities for developing graphene-based multiferroic devices.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"72 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bypassing the lattice BCS–BEC crossover in strongly correlated superconductors through multiorbital physics 通过多轨道物理绕过强相关超导体中的晶格BCS-BEC交叉

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-12-10 DOI: 10.1038/s41535-024-00706-7

Niklas Witt, Yusuke Nomura, Sergey Brener, Ryotaro Arita, Alexander I. Lichtenstein, Tim O. Wehling

{"title":"Bypassing the lattice BCS–BEC crossover in strongly correlated superconductors through multiorbital physics","authors":"Niklas Witt, Yusuke Nomura, Sergey Brener, Ryotaro Arita, Alexander I. Lichtenstein, Tim O. Wehling","doi":"10.1038/s41535-024-00706-7","DOIUrl":"https://doi.org/10.1038/s41535-024-00706-7","url":null,"abstract":"Superconductivity emerges from the spatial coherence of a macroscopic condensate of Cooper pairs. Increasingly strong binding and localization of electrons into these pairs compromises the condensate’s phase stiffness, thereby limiting critical temperatures – a phenomenon known as the BCS–BEC crossover in lattice systems. In this study, we demonstrate enhanced superconductivity in a multiorbital model of alkali-doped fullerides (A3C60) that goes beyond the limits of the lattice BCS–BEC crossover. We identify that the interplay of strong correlations and multiorbital effects results in a localized superconducting state characterized by a short coherence length but robust stiffness and a domeless rise in critical temperature with increasing pairing interaction. To derive these insights, we introduce a new theoretical framework allowing us to calculate the fundamental length scales of superconductors, namely the coherence length (ξ0) and the London penetration depth (λL), even in presence of strong electron correlations.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"21 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulating topological quantum gates in two-dimensional magnet-superconductor hybrid structures 二维磁体-超导体杂化结构拓扑量子门模拟

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-12-05 DOI: 10.1038/s41535-024-00703-w

Jasmin Bedow, Eric Mascot, Themba Hodge, Stephan Rachel, Dirk K. Morr

{"title":"Simulating topological quantum gates in two-dimensional magnet-superconductor hybrid structures","authors":"Jasmin Bedow, Eric Mascot, Themba Hodge, Stephan Rachel, Dirk K. Morr","doi":"10.1038/s41535-024-00703-w","DOIUrl":"https://doi.org/10.1038/s41535-024-00703-w","url":null,"abstract":"The creation of topological quantum gates using Majorana zero modes—an outstanding problem in the field of topological quantum computing—relies on our ability to control the braiding process in time and space. Here, we propose two-dimensional magnet-superconductor hybrid structures as a new platform for the successful implementation of topologically protected (sqrt{{sigma }_{z}})-, σz- and σx-quantum gates using Majorana zero modes. Employing a novel theoretical formalism to compute the full time-dependent many-body wave-function and utilizing a braiding protocol motivated by recent advances in electron-spin-resonance techniques we simulate quantum gates in 2D systems up to 600 sites, on timescales from a few femto- to nanoseconds. We demonstrate that the braiding process can be visualized in time and space by computing the non-equilibrium local density of states, which is proportional to the time-dependent differential conductance measured in scanning tunneling spectroscopy experiments, allowing us to directly image Majorana world lines.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"95 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142776896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spin-orbit entangled moments and magnetic exchange interactions in cobalt-based honeycomb magnets BaCo2(XO4)2 (X = P, As, Sb) 钴基蜂窝磁体BaCo2(XO4)2 （X = P, As, Sb）的自旋轨道纠缠矩和磁交换相互作用

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-12-02 DOI: 10.1038/s41535-024-00713-8

Subhasis Samanta, Fabrizio Cossu, Heung-Sik Kim

{"title":"Spin-orbit entangled moments and magnetic exchange interactions in cobalt-based honeycomb magnets BaCo2(XO4)2 (X = P, As, Sb)","authors":"Subhasis Samanta, Fabrizio Cossu, Heung-Sik Kim","doi":"10.1038/s41535-024-00713-8","DOIUrl":"https://doi.org/10.1038/s41535-024-00713-8","url":null,"abstract":"Co-based honeycomb magnets have been actively studied recently for the potential realization of emergent quantum magnetism therein such as the Kitaev spin liquid. Here we employ density functional and dynamical mean-field theory methods to examine a family of the Kitaev magnet candidates BaCo2(XO4)2 (X = P, As, Sb), where the compound with X = Sb being not synthesized yet. Our study confirms the formation of Mott insulating phase and the Jeff = 1/2 spin moments at Co2+ sites despite the presence of a sizable amount of trigonal crystal field in all three compounds. The pnictogen substitution from phosphorus to antimony significantly changes the in-plane lattice parameters and direct overlap integral between the neighboring Co ions, leading to the suppression of the Heisenberg interaction. More interestingly, the marginal antiferromagnetic nearest-neighbor Kitaev term changes sign into a ferromagnetic one and becomes sizable at the X = Sb limit. Our study suggests that the pnictogen substitution can be a viable route to continuously tune magnetic exchange interactions and to promote magnetic frustration for the realization of potential spin liquid phases in BaCo2(XO4)2.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"26 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Intrinsic second-order topological insulators in two-dimensional polymorphic graphyne with sublattice approximation 基于亚晶格近似的二维多晶石墨烯的本征二阶拓扑绝缘子

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-11-29 DOI: 10.1038/s41535-024-00710-x

Zhongjia Chen, Shaogang Xu, Zijuan Xie, Hu Xu, Hongming Weng

引用次数: 0

Quantum phase transition and composite excitations of antiferromagnetic spin trimer chains in a magnetic field 反铁磁自旋三聚体链在磁场中的量子相变和复合激发

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-11-27 DOI: 10.1038/s41535-024-00705-8

Jun-Qing Cheng, Zhi-Yao Ning, Han-Qing Wu, Dao-Xin Yao

{"title":"Quantum phase transition and composite excitations of antiferromagnetic spin trimer chains in a magnetic field","authors":"Jun-Qing Cheng, Zhi-Yao Ning, Han-Qing Wu, Dao-Xin Yao","doi":"10.1038/s41535-024-00705-8","DOIUrl":"https://doi.org/10.1038/s41535-024-00705-8","url":null,"abstract":"Motivated by recent advancements in theoretical and experimental studies of the high-energy excitations on an antiferromagnetic trimer chain, we numerically investigate the quantum phase transition and composite dynamics in this system by applying a magnetic field. The numerical methods we used include the exact diagonalization, density matrix renormalization group, time-dependent variational principle, and cluster perturbation theory. From calculating the entanglement entropy, we have revealed the phase diagram which includes the XY-I, 1/3 magnetization plateau, XY-II, and ferromagnetic phases. Both the critical XY-I and XY-II phases are characterized by the conformal field theory with a central charge c ≃ 1. By analyzing the dynamic spin structure factor, we elucidate the distinct features of spin dynamics across different phases. In the regime with weak intertrimer interaction, we identify the intermediate-energy and high-energy modes in the XY-I and 1/3 magnetization plateau phases as internal trimer excitations, corresponding to the propagating of doublons and quartons, respectively. Notably, applying a magnetic field splits the high-energy spectrum into two branches, labeled as the upper quarton and lower quarton. Furthermore, we explore the spin dynamics of a frustrated trimerized model closely related to the quantum magnet Na2Cu3Ge4O12. In the end, we extend our discuss on the possibility of the quarton Bose-Einstein condensation in the trimer systems. Our results are expected to be further verified through the inelastic neutron scattering and resonant inelastic X-ray scattering, and also provide valuable insights for exploring high-energy exotic excitations.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"25 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

3D Heisenberg universality in the van der Waals antiferromagnet NiPS3 范德华反铁磁体 NiPS3 中的三维海森堡普遍性

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-11-27 DOI: 10.1038/s41535-024-00696-6

Rajan Plumley, Sougata Mardanya, Cheng Peng, Johannes Nokelainen, Tadesse Assefa, Lingjia Shen, Nicholas Burdet, Zach Porter, Alexander Petsch, Aidan Israelski, Hongwei Chen, Jun-Sik Lee, Sophie Morley, Sujoy Roy, Gilberto Fabbris, Elizabeth Blackburn, Adrian Feiguin, Arun Bansil, Wei-Sheng Lee, Aaron M. Lindenberg, Sugata Chowdhury, Mike Dunne, Joshua J. Turner

{"title":"3D Heisenberg universality in the van der Waals antiferromagnet NiPS3","authors":"Rajan Plumley, Sougata Mardanya, Cheng Peng, Johannes Nokelainen, Tadesse Assefa, Lingjia Shen, Nicholas Burdet, Zach Porter, Alexander Petsch, Aidan Israelski, Hongwei Chen, Jun-Sik Lee, Sophie Morley, Sujoy Roy, Gilberto Fabbris, Elizabeth Blackburn, Adrian Feiguin, Arun Bansil, Wei-Sheng Lee, Aaron M. Lindenberg, Sugata Chowdhury, Mike Dunne, Joshua J. Turner","doi":"10.1038/s41535-024-00696-6","DOIUrl":"https://doi.org/10.1038/s41535-024-00696-6","url":null,"abstract":"Van der Waals (vdW) magnetic materials are comprised of layers of atomically thin sheets, making them ideal platforms for studying magnetism at the two-dimensional (2D) limit. These materials are at the center of a host of novel types of experiments, however, there are notably few pathways to directly probe their magnetic structure. We confirm the magnetic order within a single crystal of NiPS3 and show it can be accessed with resonant elastic X-ray diffraction along the edge of the vdW planes in a carefully grown crystal by detecting structurally forbidden resonant magnetic X-ray scattering. We find the magnetic order parameter has a critical exponent of β ~ 0.36, indicating that the magnetism of these vdW crystals is more adequately characterized by the three-dimensional (3D) Heisenberg universality class. We verify these findings with first-principles density functional theory, Monte-Carlo simulations, and density matrix renormalization group calculations.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"63 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multinode quantum spin liquids in extended Kitaev honeycomb models 扩展基塔耶夫蜂巢模型中的多节点量子自旋液体

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-11-26 DOI: 10.1038/s41535-024-00704-9

Jiucai Wang, B. Normand, Zheng-Xin Liu

引用次数: 0

Phase sensitive information from a planar Josephson junction 平面约瑟夫森结的相位敏感信息

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-11-25 DOI: 10.1038/s41535-024-00707-6

Andrew C. Yuan, Steven A. Kivelson

引用次数: 0

Realization of a classical Ruddlesden Popper type bilayer nickelate in Sr3Ni2−xAlxO7−δ with unusual Ni4+ 在 Sr3Ni2-xAlxO7-δ 中实现具有不寻常 Ni4+ 的经典 Ruddlesden Popper 型双层镍酸盐