npj Quantum Materials最新文献

Vortex-induced anomalies in the superconducting quantum interference patterns of topological insulator Josephson junctions 拓扑绝缘体约瑟夫森结超导量子干涉模式中的涡旋诱导反常现象

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-09-17 DOI: 10.1038/s41535-024-00684-w

Arman Rashidi, William Huynh, Binghao Guo, Sina Ahadi, Susanne Stemmer

{"title":"Vortex-induced anomalies in the superconducting quantum interference patterns of topological insulator Josephson junctions","authors":"Arman Rashidi, William Huynh, Binghao Guo, Sina Ahadi, Susanne Stemmer","doi":"10.1038/s41535-024-00684-w","DOIUrl":"https://doi.org/10.1038/s41535-024-00684-w","url":null,"abstract":"The superconducting quantum interference (SQI) patterns of Josephson junctions fabricated from hybrid structures that interface an s-wave superconductor with a topological insulator can be used to detect signatures of novel quasiparticle states. Here, we compare calculated and experimental SQI patterns obtained from hybrid junctions fabricated on cadmium arsenide, a two-dimensional topological insulator. The calculations account for the effects of Abrikosov (anti-) vortices in the superconducting contacts. They describe the experimentally observed deviations of the SQI from an ideal Fraunhofer pattern, including anomalous phase shifts, node lifting, even/odd modulations of the lobes, irregular lobe spacing, and an asymmetry in the positive/negative magnetic field. We also show that under a current bias, these vortices enter the electrodes even if there is no intentionally applied external magnetic field. The results show that Abrikosov vortices in the electrodes of the junctions can explain many of the observed anomalies in the SQI patterns of topological insulator Josephson junctions.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142235244","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

Unconventional spin textures emerging from a universal symmetry theory of spin-momentum locking 自旋动量锁定的普遍对称理论所产生的非常规自旋纹理

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-09-14 DOI: 10.1038/s41535-024-00682-y

Yuntian Liu, Jiayu Li, Pengfei Liu, Qihang Liu

引用次数: 0

Incommensurate magnetic order in an axion insulator candidate EuIn2As2 investigated by NMR measurement 通过核磁共振测量研究轴心绝缘体候选体 EuIn2As2 中的不相称磁序

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-09-12 DOI: 10.1038/s41535-024-00680-0

Hikaru Takeda, Jian Yan, Zhongzhu Jiang, Xuan Luo, Yuping Sun, Minoru Yamashita

{"title":"Incommensurate magnetic order in an axion insulator candidate EuIn2As2 investigated by NMR measurement","authors":"Hikaru Takeda, Jian Yan, Zhongzhu Jiang, Xuan Luo, Yuping Sun, Minoru Yamashita","doi":"10.1038/s41535-024-00680-0","DOIUrl":"https://doi.org/10.1038/s41535-024-00680-0","url":null,"abstract":"Magnetic topological insulators exhibit unique electronic states due to the interplay between the electronic topology and the spin structure. The antiferromagnetic metal EuIn2As2 is a prominent candidate material in which exotic topological phases, including an axion insulating state, are theoretically predicted depending on the magnetic structure of the Eu2+ moments. Here, we report experimental results of the nuclear magnetic resonance (NMR) measurements of all the nuclei in EuIn2As2 to investigate the coupling between the magnetic moments in the Eu ions and the conduction electrons in In2As2 layers and the magnetic structure. The 75As and 115In NMR spectra observed at zero external magnetic fields reveal the appearance of internal fields of 4.9 and 3.6 T, respectively, at the lowest temperature, suggesting a strong coupling between the conduction electrons in the In2As2 layer and the ordered magnetic moments in the Eu ions. The 75As NMR spectra under in-plane external magnetic fields show broad distributions of the internal fields produced by an incommensurate fan-like spin structure which turns into a forced ferromagnetic state above 0.7 T. We propose a spin reorientation process that an incommensurate helical state at zero external magnetic field quickly changes into a fan state by applying a slight magnetic field.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142170842","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

d-wave charge-4e superconductivity from fluctuating pair density waves 来自波动对密度波的 d 波电荷-4e 超导性

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-09-05 DOI: 10.1038/s41535-024-00674-y

Yi-Ming Wu, Yuxuan Wang

引用次数: 0

Kinetic ferromagnetism and topological magnons of the hole-doped Kitaev spin liquid 掺孔基塔耶夫自旋液体的动铁磁性和拓扑磁子

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-09-04 DOI: 10.1038/s41535-024-00678-8

Hui-Ke Jin, Wilhelm Kadow, Michael Knap, Johannes Knolle

引用次数: 0

Hybrid spin-orbit exciton-magnon excitations in FePS3 FePS3 中的混合自旋-轨道激子-磁子激发

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-08-22 DOI: 10.1038/s41535-024-00675-x

Ramesh Dhakal, Samuel Griffith, Stephen M. Winter

引用次数: 0

Unraveling magneto-elastoresistance in the Dirac nodal-line semi-metal ZrSiSe 揭示狄拉克结线半金属 ZrSiSe 中的磁极电阻

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-08-20 DOI: 10.1038/s41535-024-00670-2

J. F. Linnartz, A. Kool, J. P. Lorenz, C. S. A. Müller, M. R. van Delft, R. Singha, L. M. Schoop, N. E. Hussey, A. de Visser, S. Wiedmann

{"title":"Unraveling magneto-elastoresistance in the Dirac nodal-line semi-metal ZrSiSe","authors":"J. F. Linnartz, A. Kool, J. P. Lorenz, C. S. A. Müller, M. R. van Delft, R. Singha, L. M. Schoop, N. E. Hussey, A. de Visser, S. Wiedmann","doi":"10.1038/s41535-024-00670-2","DOIUrl":"https://doi.org/10.1038/s41535-024-00670-2","url":null,"abstract":"Quantum materials are often characterized by a marked sensitivity to minute changes in their physical environment, a property that can lead to new functionalities and thereby, to novel applications. One such key property is the magneto-elastoresistance (MER), the change in magnetoresistance (MR) of a metal induced by uniaxial strain. Understanding and modeling this response can prove challenging, particularly in systems with complex Fermi surfaces. Here, we present a thorough analysis of the MER in the nearly compensated Dirac nodal-line semi-metal ZrSiSe. Small amounts of strain (0.27%) lead to large changes (7%) in the MR. Subsequent analysis reveals that the MER response is driven primarily by a change in transport mobility that varies linearly with the applied strain. This study showcases how the effect of strain tuning on the electrical properties can be both qualitatively and quantitatively understood. A complementary Shubnikov-de Haas oscillation study sheds light on the root of this change in quantum mobility. Moreover, we unambiguously show that the Fermi surface consists of distinct electron and hole pockets revealed in quantum oscillation measurements originating from magnetic breakdown.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142007542","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

Gauge field dynamics in multilayer Kitaev spin liquids 多层基塔耶夫自旋液体中的量子场动力学

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-08-18 DOI: 10.1038/s41535-024-00673-z

Aprem P. Joy, Achim Rosch

{"title":"Gauge field dynamics in multilayer Kitaev spin liquids","authors":"Aprem P. Joy, Achim Rosch","doi":"10.1038/s41535-024-00673-z","DOIUrl":"https://doi.org/10.1038/s41535-024-00673-z","url":null,"abstract":"The Kitaev spin liquid realizes an emergent static ({{mathbb{Z}}}_{2}) gauge field with vison excitations coupled to Majorana fermions. We consider Kitaev models stacked on top of each other, weakly coupled by Heisenberg interaction ∝ J⊥. This inter-layer coupling breaks the integrability of the model and makes the gauge fields dynamic. Conservation laws and topology keep single visons immobile. However, an inter-layer vison pairs can hop with a hopping amplitude linear in J⊥ confined to the layer, but their motion is strongly influenced by the type of stacking. For AA stacking, an interlayer pair has a two-dimensional motion but for AB or ABC stacking, sheet conservation laws restrict its motion to a one-dimensional channel within the plane. For all stacking types, an intra-layer vison-pair is constrained to move out-of-plane only. Depending on the anisotropy of the Kitaev couplings Kx, Ky, Kz, the intra-layer vison pairs can display either coherent tunnelling or purely incoherent hopping. When a magnetic field opens a gap for Majorana fermions, there exist two types of intra-layer vison pairs - a bosonic and a fermionic one. Only the bosonic pair obtains a hopping rate linear in J⊥. We use our results to identify the leading instabilities of the spin liquid phase induced by the inter-layer coupling.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142002779","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

High-TC superconductivity in La3Ni2O7 based on the bilayer two-orbital t-J model 基于双层双轨道 t-J 模型的 La3Ni2O7 中的高 TC 超导性

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-08-13 DOI: 10.1038/s41535-024-00668-w

Zhihui Luo, Biao Lv, Meng Wang, Wéi Wú, Dao-Xin Yao

{"title":"High-TC superconductivity in La3Ni2O7 based on the bilayer two-orbital t-J model","authors":"Zhihui Luo, Biao Lv, Meng Wang, Wéi Wú, Dao-Xin Yao","doi":"10.1038/s41535-024-00668-w","DOIUrl":"https://doi.org/10.1038/s41535-024-00668-w","url":null,"abstract":"The recently discovered high-Tc superconductor La3Ni2O7 has sparked renewed interest in unconventional superconductivity. Here we study superconductivity in pressurized La3Ni2O7 based on a bilayer two-orbital t−J model, using the renormalized mean-field theory. Our results reveal a robust s±-wave pairing driven by the inter-layer ({d}_{{z}^{2}}) magnetic coupling, which exhibits a transition temperature within the same order of magnitude as the experimentally observed Tc ~ 80 K. We establish a comprehensive superconducting phase diagram in the doping plane. Notably, the La3Ni2O7 under pressure is found to be situated roughly in the optimal doping regime of the phase diagram. When the ({d}_{{x}^{2}-{y}^{2}}) orbital becomes close to half-filling, d-wave and d + is pairing can emerge from the system. We discuss the interplay between Fermi surface topology and different pairing symmetries. The stability of the s±-wave pairing against Hund’s coupling and other magnetic exchange couplings is discussed.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141980978","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

Excellent thermoelectric performance of Fe2NbAl alloy induced by strong crystal anharmonicity and high band degeneracy 强晶体非谐波性和高带退变性诱导的 Fe2NbAl 合金的优异热电性能

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2024-08-13 DOI: 10.1038/s41535-024-00671-1

Xianfeng Ye, Jian Yu, Shaoqiu Ke, Dong Liang, Tiantian Chen, Chengshan Liu, Wenjie Xu, Longzhou Li, Wanting Zhu, Xiaolei Nie, Ping Wei, Wenyu Zhao, Qingjie Zhang

{"title":"Excellent thermoelectric performance of Fe2NbAl alloy induced by strong crystal anharmonicity and high band degeneracy","authors":"Xianfeng Ye, Jian Yu, Shaoqiu Ke, Dong Liang, Tiantian Chen, Chengshan Liu, Wenjie Xu, Longzhou Li, Wanting Zhu, Xiaolei Nie, Ping Wei, Wenyu Zhao, Qingjie Zhang","doi":"10.1038/s41535-024-00671-1","DOIUrl":"https://doi.org/10.1038/s41535-024-00671-1","url":null,"abstract":"Full-Heusler alloys with earth-abundant elements exhibit high mechanical strength and favorable electrical transport behavior, but their high intrinsic lattice thermal conductivity limits potential thermoelectric application. Here, the thermoelectric transport properties of Fe-based Full-Heusler Fe2MAl (M = V, Nb, Ta) alloys are comprehensively investigated utilizing density functional theory. The results suggest that Fe2NbAl exhibits exceptionally low lattice thermal conductivity due to low phonon velocities and weakly bound Nb atoms. In Fe2NbAl, the underbonding of the Nb atoms leads large Grüneisen parameters and high anharmonic scattering rates of low-frequency acoustic phonon. Meanwhile, the high band degeneracy and large electrical conductivity lead to a maximum p-type power factor of 255.6 μW·K−2·cm−1 at 900 K. The combination of low lattice thermal conductivity and favorable electrical transport properties leads a maximum p-type dimensionless figure of merit of 1.7. Our work indicates Fe2NbAl, as a low-cost, environmentally friendly, is a potential high-performance p-type thermoelectric material.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141973794","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