npj Quantum Materials最新文献_第2页

Anisotropic non-Fermi liquid and dynamical Planckian scaling of a quasi-kagome Kondo lattice system 准kagome Kondo晶格系统的各向异性非费米液体和动态普朗克标度

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2025-08-05 DOI: 10.1038/s41535-025-00797-w

Shin-ichi Kimura, Muhammad Frassetia Lubis, Hiroshi Watanabe, Yasuyuki Shimura, Toshiro Takabatake

{"title":"Anisotropic non-Fermi liquid and dynamical Planckian scaling of a quasi-kagome Kondo lattice system","authors":"Shin-ichi Kimura, Muhammad Frassetia Lubis, Hiroshi Watanabe, Yasuyuki Shimura, Toshiro Takabatake","doi":"10.1038/s41535-025-00797-w","DOIUrl":"https://doi.org/10.1038/s41535-025-00797-w","url":null,"abstract":"At the quantum critical point of correlated materials, a non-Fermi liquid state appears where electron correlations continuously develop to very low temperatures. The relaxation time of the interacted electrons, namely quasiparticles, is scaled with the Planckian time, ℏ/kBT. However, there is a debate over whether heavy-fermion systems can obey the Planckian time. In the optical conductivity spectra, the Drude response will appear as the scaling of ℏω/kBT as the dynamical Planckian scaling (DPS). Here, we report the non-Fermi liquid behavior in the Drude response of a candidate for such materials, the quasi-kagome Kondo lattice CeRhSn. Even though the material shows a strong valence fluctuation, renormalized Drude responses observed at the photon energy below 100 meV are characterized by non-Fermi-liquid-like scattering rate 1/τ. The heavy carriers’ Drude response only for the Ce quasi-kagome plane obeyed DPS below 80 K, suggesting the anisotropic quantum criticality with the strong c-f hybridization.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"29 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144778533","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

Time-reversal symmetry breaking, collective modes, and Raman spectrum in pair-density-wave states 时间反转对称性破缺，集体模式，和对密度波态的拉曼光谱

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2025-08-01 DOI: 10.1038/s41535-025-00808-w

Yi-Ming Wu, Andrey V. Chubukov, Yuxuan Wang, Steven A. Kivelson

引用次数: 0

Altermagnetism and strain induced altermagnetic transition in Cairo pentagonal monolayer Cairo五角形单层的电磁学及应变诱导的电磁跃迁

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2025-07-25 DOI: 10.1038/s41535-025-00793-0

Shuyi Li, Yu Zhang, Adrian Bahri, Xiaoliang Zhang, Chunjing Jia

引用次数: 0

Quantum decoherence by magnetic fluctuations in a magnetic topological insulator 磁性拓扑绝缘体中磁涨落的量子退相干

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2025-07-23 DOI: 10.1038/s41535-025-00795-y

Ruben Saatjian, Simon Dovrén, Kohtaro Yamakawa, Ryan S. Russell, James G. Analytis, John W. Harter

{"title":"Quantum decoherence by magnetic fluctuations in a magnetic topological insulator","authors":"Ruben Saatjian, Simon Dovrén, Kohtaro Yamakawa, Ryan S. Russell, James G. Analytis, John W. Harter","doi":"10.1038/s41535-025-00795-y","DOIUrl":"https://doi.org/10.1038/s41535-025-00795-y","url":null,"abstract":"In magnetic topological insulators, spontaneous time-reversal symmetry breaking by intrinsic magnetic order can gap the topological surface spectrum, resulting in exotic properties like axion electrodynamics, the quantum anomalous Hall effect, and other topological magnetoelectric responses. Understanding the magnetic order and its coupling to topological states is essential to harness these properties. Here, we leverage near-resonant magnetic dipole optical second harmonic generation to probe magnetic fluctuations in the candidate axion insulator EuSn2(As,P)2 across its antiferromagnetic phase boundary. We observe a pronounced dimensional crossover in the quantum decoherence induced by magnetic fluctuations, whereby two-dimensional in-plane ferromagnetic correlations at high temperatures give way to three-dimensional long-range order at the Néel temperature. We also observe the breaking of rotational symmetry within the long-range-ordered antiferromagnetic state and map out the resulting spatial domain structure. More generally, we demonstrate the unique capabilities of nonlinear optical spectroscopy to study quantum coherence and fluctuations in magnetic quantum materials.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"25 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144684818","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

Strong coupling theory of superconductivity and ferroelectric quantum criticality in metallic SrTiO3 金属SrTiO3超导性与铁电量子临界性强耦合理论

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2025-07-23 DOI: 10.1038/s41535-025-00798-9

Sudip Kumar Saha, M. N. Gastiasoro, Jonathan Ruhman, Avraham Klein

{"title":"Strong coupling theory of superconductivity and ferroelectric quantum criticality in metallic SrTiO3","authors":"Sudip Kumar Saha, M. N. Gastiasoro, Jonathan Ruhman, Avraham Klein","doi":"10.1038/s41535-025-00798-9","DOIUrl":"https://doi.org/10.1038/s41535-025-00798-9","url":null,"abstract":"Superconductivity in doped SrTiO3 has remained an enduring mystery for over 50 years. The material’s status as a “quantum\" ferroelectric metal, characterized by a soft polar mode, suggests that quantum criticality could play a pivotal role in the emergence of its superconducting state. We show that the system is amenable to a strong coupling (Eliashberg) pairing analysis, with the dominant coupling to the soft mode being a “dynamical” Rashba coupling. We compute the expected Tc for the entire phase diagram, all the way to the quantum critical point and beyond. We demonstrate that the linear coupling is sufficient to obtain a rough approximation of the experimentally measured phase diagram, but that nonlinear coupling terms are crucial in reproducing the finer features in the ordered phase. The primary role of nonlinear terms at the peak of the superconducting dome is to enhance the effective linear coupling induced by the broken order, shifting the dome’s maximum into the ordered phase. Our theory quantitatively reproduces the three-dimensional experimental phase diagram in the space of carrier density, distance from the quantum critical point and temperature, and allows us to estimate microscopic parameters from the experimental data.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"110 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694119","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

Large unconventional anomalous Hall effect far above room temperature in epitaxial Fe3Ga4 films 远高于室温的Fe3Ga4外延薄膜中存在大量非常规反常霍尔效应

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2025-07-21 DOI: 10.1038/s41535-025-00802-2

Jing Meng, Huali Yang, Yu Shen, Kun Zheng, Hongru Wang, Yuhao Wang, Keqi Xia, Bocheng Yu, Xiaoyan Zhu, Baiqing Lv, Yaobo Huang, Jie Ma, Dariusz Jakub Gawryluk, Toni Shiroka, Zhenzhong Yang, Yang Xu, Qingfeng Zhan, Tian Shang

{"title":"Large unconventional anomalous Hall effect far above room temperature in epitaxial Fe3Ga4 films","authors":"Jing Meng, Huali Yang, Yu Shen, Kun Zheng, Hongru Wang, Yuhao Wang, Keqi Xia, Bocheng Yu, Xiaoyan Zhu, Baiqing Lv, Yaobo Huang, Jie Ma, Dariusz Jakub Gawryluk, Toni Shiroka, Zhenzhong Yang, Yang Xu, Qingfeng Zhan, Tian Shang","doi":"10.1038/s41535-025-00802-2","DOIUrl":"https://doi.org/10.1038/s41535-025-00802-2","url":null,"abstract":"Noncoplanar spin textures usually exhibit a finite scalar spin chirality (SSC) that can generate effective magnetic fields and lead to additional contributions to the Hall effect, namely topological or unconventional anomalous Hall effect (UAHE). Unlike topological spin textures (e.g., magnetic skyrmions), materials that exhibit fluctuation-driven SSC and UAHE are rare. So far, their realization has been limited to either low temperatures or high magnetic fields, both of which are unfavorable for practical applications. Identifying new materials that exhibit UAHE in a low magnetic field at room temperature is therefore essential. Here, we report the discovery of a large UAHE far above room temperature in epitaxial Fe3Ga4 films, where the fluctuation-driven SSC stems from the field-induced transverse-conical-spiral phase. Considering their epitaxial nature and the large UAHE stabilized at room temperature in a low magnetic field, Fe3Ga4 films represent an exciting, albeit rare, example of a promising material for spintronic devices.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"208 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144669722","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

Magnetic excitations and absence of charge order in the van der Waals ferromagnet Fe4.75GeTe2 范德华铁磁体Fe4.75GeTe2的磁激发与荷序缺失

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2025-07-21 DOI: 10.1038/s41535-025-00803-1

V. K. Bhartiya, T. Kim, J. Li, T. P. Darlington, D. J. Rizzo, Y. Gu, S. Fan, C. Nelson, J. W. Freeland, X. Xu, D. N. Basov, J. Pelliciari, A. F. May, C. Mazzoli, V. Bisogni

{"title":"Magnetic excitations and absence of charge order in the van der Waals ferromagnet Fe4.75GeTe2","authors":"V. K. Bhartiya, T. Kim, J. Li, T. P. Darlington, D. J. Rizzo, Y. Gu, S. Fan, C. Nelson, J. W. Freeland, X. Xu, D. N. Basov, J. Pelliciari, A. F. May, C. Mazzoli, V. Bisogni","doi":"10.1038/s41535-025-00803-1","DOIUrl":"https://doi.org/10.1038/s41535-025-00803-1","url":null,"abstract":"Understanding the ground state of van der Waals (vdW) magnets is crucial for designing devices leveraging these platforms. Here, we investigate the magnetic excitations and charge order in Fe4.75GeTe2, a vdW ferromagnet with ≈ 315 K Curie temperature. Using Fe L3-edge resonant inelastic X-ray scattering, we observe a dual nature of magnetic excitations, comprising a coherent magnon and a broad non-dispersive continuum extending up to 150 meV, 50% higher than in Fe2.72GeTe2. The continuum intensity is sinusoidally modulated along the stacking direction L, with a period matching the inter-slab distance. Our results indicate that while the dual character of the magnetic excitations is generic to Fe-Ge-Te vdW magnets, Fe4.75GeTe2exhibits a longer out-of-plane magnetic correlation length, suggesting enhanced 3D magnetic character. Furthermore, resonant X-ray diffraction reveals that previously reported ±(1/3, 1/3, L) peaks originate from crystal structure rather than from charge order.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"83 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144677301","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

Perspective: an X-ray view of the coherent driving of materials 透视：材料相干驱动的x射线视图

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2025-07-19 DOI: 10.1038/s41535-025-00799-8

Steven L. Johnson, Urs Staub

引用次数: 0

Berry curvature-induced transport signature for altermagnetic order 交变磁阶的Berry曲率诱导输运特征

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2025-07-17 DOI: 10.1038/s41535-025-00805-z

T. Farajollahpour, R. Ganesh, K. V. Samokhin

{"title":"Berry curvature-induced transport signature for altermagnetic order","authors":"T. Farajollahpour, R. Ganesh, K. V. Samokhin","doi":"10.1038/s41535-025-00805-z","DOIUrl":"https://doi.org/10.1038/s41535-025-00805-z","url":null,"abstract":"Altermagnetism has been detected in several materials using spin-sensitive probes. These measurements require rather complex setups that make it challenging to track variations in altermagnetic order, e.g., to identify a temperature-tuned altermagnetic phase transition. We propose a simple transport measurement that can probe the order parameter for d-wave altermagnetism. We suggest magnetoconductivity anisotropy—the difference between the two principal values of the magnetoconductivity tensor. This quantity can be easily measured as a function of temperature, without any spin-selective apparatus. It acquires a nonzero value in a C4K phase, where C4 rotations and time reversal K are not symmetries but their combination is. This effect can be traced to the modification of phase space density due to Berry curvature, which we demonstrate using semiclassical equations of motion for band electrons. As an illustration, we build a minimal tight-binding model with altermagnetic order that breaks C4 and K symmetries while preserving C4K.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"109 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144652515","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

Strain-induced moiré polar vortex in twisted paraelectric freestanding bilayers 扭曲对电独立双层中应变诱导的涡流极涡

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2025-07-11 DOI: 10.1038/s41535-025-00796-x

Yixuan Zhang, Haozhi Sha, Xueyun Wang, Deshan Liang, Jing Wang, Qian Li, Rong Yu, Houbing Huang

{"title":"Strain-induced moiré polar vortex in twisted paraelectric freestanding bilayers","authors":"Yixuan Zhang, Haozhi Sha, Xueyun Wang, Deshan Liang, Jing Wang, Qian Li, Rong Yu, Houbing Huang","doi":"10.1038/s41535-025-00796-x","DOIUrl":"https://doi.org/10.1038/s41535-025-00796-x","url":null,"abstract":"The recent discovery of two-dimensional (2D) moiré vortex patterns reveals new possibilities for nanoscale polar topology engineering and unexplored physical phenomena. However, the physical origin and detailed topological characteristics of these moiré vortex patterns have still not been understood. In this study, based on the lattice polarization coupling of ferroelectrics, we analytically determined the discovered strain state in twisted bilayer systems by elastic theory. Furthermore, the resulting moiré vortex patterns are investigated via phase-field simulations. Our findings demonstrate that the in-plane moiré vortex patterns arise from periodic displacement vorticity induced by moiré stacking. The complex interplay among elastic, flexoelectric, and gradient energy is identified as the energetic driving force behind the formation of these vortex patterns. Through three-dimensional simulation, we reveal that each polar vortex exhibits significant in-plane divergence and out-of-plane chirality, with the latter being tunable via external electric fields. These findings offer new avenues for manipulating nanoscale ferroelectric topologies.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"35 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144603003","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