npj Quantum Materials最新文献_第7页

Spin-supersolidity induced quantum criticality and magnetocaloric effect in the triangular-lattice antiferromagnet Rb2Co(SeO3)2 三角形晶格反铁磁体Rb2Co(SeO3)2的自旋超固体诱导量子临界和磁热效应

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-04-15 DOI: 10.1038/s41535-026-00881-9

Yi Cui, Zhanlong Wu, Zhongcen Sun, Kefan Du, Jun Luo, Shuo Li, Jie Yang, Jinchen Wang, Rui Zhou, Qian Chen, Yoshimitsu Kohama, Atsuhiko Miyata, Zhuo Yang, Rong Yu, Weiqiang Yu

{"title":"Spin-supersolidity induced quantum criticality and magnetocaloric effect in the triangular-lattice antiferromagnet Rb2Co(SeO3)2","authors":"Yi Cui, Zhanlong Wu, Zhongcen Sun, Kefan Du, Jun Luo, Shuo Li, Jie Yang, Jinchen Wang, Rui Zhou, Qian Chen, Yoshimitsu Kohama, Atsuhiko Miyata, Zhuo Yang, Rong Yu, Weiqiang Yu","doi":"10.1038/s41535-026-00881-9","DOIUrl":"https://doi.org/10.1038/s41535-026-00881-9","url":null,"abstract":"We performed high-field magnetization, magnetocaloric effect (MCE), and NMR measurements on the Ising triangular-lattice antiferromagnet Rb2Co(SeO3)2. The observations of the 1/3-magnetization plateau, the NMR line splits, and the thermal activation behaviors of the spin-lattice relaxation rate 1/T1 between 2 and 15.8 T provide unambiguous evidence of a gapped up–up–down (UUD) magnetic ordered phase. For fields between 15.8 and 18.5 T, the anomaly in the magnetic susceptibility, the slow saturation of the NMR line spectral ratio with temperature, the decrease of the NMR line split with field, and the power-law temperature dependence of 1/T1 provide evidence consistent with a spin supersolid with gapless spin excitations. Further increasing the field, the Grüneisen ratio, extracted from the MCE data, reveals a continuous quantum phase transition at HC ≈ 19.5 T and a universal quantum critical scaling with the exponents νz ≈ 1. Near HC, the large high-temperature MCE signal and the broad peaks in the NMR Knight shift and 1/T1, manifest the strong spin fluctuations driven by both magnetic frustration and quantum criticality.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"22 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147685124","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

Inverse Lieb materials: altermagnetism and more 反Lieb材料：电磁学和更多

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-04-10 DOI: 10.1038/s41535-026-00880-w

Po-Hao Chang, Kirill D. Belashchenko, Igor I. Mazin

{"title":"Inverse Lieb materials: altermagnetism and more","authors":"Po-Hao Chang, Kirill D. Belashchenko, Igor I. Mazin","doi":"10.1038/s41535-026-00880-w","DOIUrl":"https://doi.org/10.1038/s41535-026-00880-w","url":null,"abstract":"The Lieb lattice, originally proposed for cuprate superconductors, has gained new attention in the emerging field of altermagnetism as a minimal analytical model for the latter. While the inverse Lieb lattice (ILL) was once considered purely theoretical, several materials with this motif have recently been discovered. Its unique geometry supports complex magnetic orders driven by geometric frustration, offering high tunability. In this work, we provide comprehensive insights into ILL magnetic phases and establish guidelines for identifying altermagnets. Using a Heisenberg model, we first construct phase diagrams to elucidate the mechanisms underlying experimental magnetic phases. We then bridge theory and experiment via density functional theory (DFT) calculations on existing ILL compounds, finding results consistent with experimental data. Notably, we identified a trend linking d-shell filling to magnetic order, where dx (x≤5) configurations show a propensity for altermagnetism. We also highlight Sr2CrO2Cr2OAs2 as a promising metallic altermagnet with highly anisotropic J2 exchange and a high Néel temperature (~600 K). Finally, our magnon spectra calculations confirm that chiral splittings correlate directly with anisotropies between inequivalent J2 interactions.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"29 2 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147655965","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

Anisotropic multi-Q order in CoxTaS2 CoxTaS2的各向异性多q顺序

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-04-09 DOI: 10.1038/s41535-026-00856-w

Jonathon Kruppe, Josue Rodriguez, Catherine Xu, James Analytis, Joseph Orenstein, Veronika Sunko

引用次数: 0

Multiple topological states in LaAgAs2, a failed square-net semimetal 失效方网半金属LaAgAs2的多拓扑态

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-04-08 DOI: 10.1038/s41535-026-00879-3

Yang Liu, Tongrui Li, Xixi Yuan, Nour Maraytta, Alexei V. Fedorov, Asish K. Kundu, Turgut Yilmaz, Elio Vescovo, Xueliang Wu, Long Zhang, Mingquan He, Yisheng Chai, Xiaoyuan Zhou, Michael Merz, Zhe Sun, Huixia Fu, Tonica Valla, Aifeng Wang

{"title":"Multiple topological states in LaAgAs2, a failed square-net semimetal","authors":"Yang Liu, Tongrui Li, Xixi Yuan, Nour Maraytta, Alexei V. Fedorov, Asish K. Kundu, Turgut Yilmaz, Elio Vescovo, Xueliang Wu, Long Zhang, Mingquan He, Yisheng Chai, Xiaoyuan Zhou, Michael Merz, Zhe Sun, Huixia Fu, Tonica Valla, Aifeng Wang","doi":"10.1038/s41535-026-00879-3","DOIUrl":"https://doi.org/10.1038/s41535-026-00879-3","url":null,"abstract":"The rational design of new materials emerges as an important direction to explore new topological materials, which is based on the understanding of the correlation between crystal and electronic structures. In this paper, we perform a comprehensive study on the crystal and electronic structures in LaAgAs2 through a combination of single-crystal x-ray diffraction (XRD), quantum oscillation, and angle-resolved photoemission spectroscopy (ARPES) experimental measurements, and density functional theory (DFT) calculations. Single-crystal XRD measurements reveal that LaAgAs2 crystallizes into a HfCuSi2-derived structure with the square net distorted into cis-trans chains. Quantum oscillation measurements reveal two frequencies with small effective masses and quasi-two-dimensional (2D) characters. ARPES measurements reveal an electronic structure strikingly different from the square-net-based semimetals, such as LaAgSb2. The Fermi surface is quasi-two-dimensional (2D), with Dirac-like hole pockets at the zone center and a quasi-1D elliptical electron pocket at the zone boundary. Based on the DFT calculations, the measured electronic structure can be well understood regarding the cis-trans distortion, which transforms the two-dimensional square net-derived Dirac bands into quasi-1D trivial bands. Intriguingly, multiple topological states can be identified around the zone center, including a nontrivial Z2 topological surface state and a bulk Dirac state. Our study clarifies the impact of cis-trans distortion and identifies LaAgAs2 as a topological material with multiple topological states near the Fermi level, providing a guideline for intentionally designing new topological materials.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"5 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147631087","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

Topological altermagnetic Josephson junctions 拓扑交替约瑟夫森结

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-04-01 DOI: 10.1038/s41535-026-00874-8

Grant Z. X. Yang, Zi-Ting Sun, Ying-Ming Xie, K. T. Law

{"title":"Topological altermagnetic Josephson junctions","authors":"Grant Z. X. Yang, Zi-Ting Sun, Ying-Ming Xie, K. T. Law","doi":"10.1038/s41535-026-00874-8","DOIUrl":"https://doi.org/10.1038/s41535-026-00874-8","url":null,"abstract":"Planar Josephson junctions are pivotal for engineering topological superconductivity, yet are severely hindered by the orbital effects induced by in-plane magnetic fields, or the stray fields introduced by the use of ferromagnets. Here, we propose the generic topological altermagnetic Josephson junctions (TAJJs) as a solution to this critical problem. By leveraging the anisotropic spin-polarized band splitting and zero net magnetization attributes of altermagnets, our proposed TAJJs effectively mitigate the detrimental orbital effects while hosting Majorana zero modes (MZMs) at both ends of the junction in the complete absence of external fields. Specifically, we demonstrate that MZMs emerge robustly in ({d}_{{x}^{2}-{y}^{2}})-wave TAJJs but vanish in the dxy-wave configuration, establishing the altermagnet orientation as an intrinsic control knob of topological superconductivity. The distinct out-of-plane spin-polarization of the MZMs provides an experimental signature for the spin-resolved measurement. Furthermore, by harnessing the synergy between the ({d}_{{x}^{2}-{y}^{2}})-wave altermagnet and anisotropic superconductivity, our proposal extends naturally to high-temperature superconducting platforms. Our work establishes altermagnets as a versatile paradigm for realizing MZMs, bridging conceptual innovations with scalable quantum architectures devoid of orbital effects and stray fields.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"18 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147585912","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

Phonon thermal Hall effect: the roles of disorder, annealing, and metallic contacts 声子热霍尔效应：无序、退火和金属接触的作用

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-03-24 DOI: 10.1038/s41535-026-00876-6

Qiaochao Xiang, Xiaokang Li, Xiaodong Guo, Kamran Behnia, Zengwei Zhu

{"title":"Phonon thermal Hall effect: the roles of disorder, annealing, and metallic contacts","authors":"Qiaochao Xiang, Xiaokang Li, Xiaodong Guo, Kamran Behnia, Zengwei Zhu","doi":"10.1038/s41535-026-00876-6","DOIUrl":"https://doi.org/10.1038/s41535-026-00876-6","url":null,"abstract":"The phonon thermal Hall effect (THE) is a ubiquitous yet poorly understood phenomenon in insulators. Its microscopic origin remains debated, partly due to significant sample-dependent variations that hint at uncontrolled experimental parameters. Using SrTiO3 as a model system, we identify disorder and uncontrolled strain as suppressors of a thermal Hall signal. Crystals with high thermal conductivity exhibit a substantial thermal Hall angle ∇Ty/∇Tx (up to 0.3% at 9 T), whereas the effect is virtually absent in disordered samples. Crucially, annealing (in air atmosphere) these disordered samples partially restores the THE (~0.1% at 9 T) with little effect on the longitudinal thermal conductivity. This decoupling reveals that the amplitude of THE is not simply set by the phonon mean free path. Furthermore, measurements performed with metallic and insulating contacts yield identical results on the same sample. This definitely rules out parasitic signals as the effect’s origin. Our work, by establishing the phonon THE as an intrinsic property of the crystal lattice and extremely sensitive to disorder, sharply constrains theoretical scenarios.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"14 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147506121","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

Fermi liquid and isotropic superconductivity of Hund scenario for bilayer nickelates 双层镍酸盐的费米液体和各向同性超导

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-03-20 DOI: 10.1038/s41535-026-00871-x

Jiangfan Wang, Yi-feng Yang

引用次数: 0

Spin order and spin excitation spectra of spin-1/2 tetramer chains 自旋-1/2四聚体链的自旋顺序和自旋激发谱

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-03-18 DOI: 10.1038/s41535-026-00855-x

Junli Li, Jun-Qing Cheng, Trinanjan Datta, Dao-Xin Yao

{"title":"Spin order and spin excitation spectra of spin-1/2 tetramer chains","authors":"Junli Li, Jun-Qing Cheng, Trinanjan Datta, Dao-Xin Yao","doi":"10.1038/s41535-026-00855-x","DOIUrl":"https://doi.org/10.1038/s41535-026-00855-x","url":null,"abstract":"We investigate the spin dynamics of a 1D spin-1/2 Heisenberg tetramer chain. Employing a combination of density matrix renormalization group, quantum renormalization group, and perturbation theory techniques, we compute the energy levels and the quantum phase diagram, analyze the phase transitions, and evaluate the dynamical structure factor (DSF), which is related to the inelastic neutron scattering (INS) spectrum and the resonant inelastic x-ray scattering (RIXS) spectrum of fractionalized and collective excitations. Our calculations suggest that the chain can transition between a hidden Z2 × Z2 discrete symmetry preserving tetramer phase and a Haldane phase with non-vanishing string order that breaks the hidden symmetry. These two gapped phases are intervened by an intermediate deconfined quantum critical state comprising of free spins and three-site doublets, which is a gapless critical phase with deconfined spinons that can be detected either by INS or L-edge RIXS. We find that the tetramer chain can support fractionalized (spinon) and collective (triplon and quinton) excitations. In the ferromagnetic intra-tetramer limit, the chain can support a quinton excitation which has a five-fold degenerate excited state. String order parameter calculations suggest CuInVO5 should be in a Haldane-like phase whose INS or L-edge RIXS spectrum can support observable single-spin excitations including triplon and quinton excitations. We also identify possible two-particle excitations (two-singlon, two-triplon, triplon-quinton, and two-quinton excitations) resulting from the double spin-flip effect in the K-edge RIXS spectrum.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"38 6 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496807","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-tuned ferroelectric transitions in HfO2: role of X2−{X}_{2}^{-} mode in ferroelectric instabilities HfO2中应变调谐铁电跃迁：X2−{X}_{2}^{-}模式在铁电不稳定性中的作用

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-03-18 DOI: 10.1038/s41535-026-00870-y

Ilyoung Lee, Wontae Lee, Jaejun Yu

{"title":"Strain-tuned ferroelectric transitions in HfO2: role of X2−{X}_{2}^{-} mode in ferroelectric instabilities","authors":"Ilyoung Lee, Wontae Lee, Jaejun Yu","doi":"10.1038/s41535-026-00870-y","DOIUrl":"https://doi.org/10.1038/s41535-026-00870-y","url":null,"abstract":"Recent studies have identified HfO2 as a promising ferroelectric material for thin films, highlighting its potential as a state-of-the-art option for future ferroelectric applications. However, due to the complexity of the fabrication process, the underlying mechanism of the phase transition to Pca21 is still not fully understood. In this study, we aim to clarify the phase transition pathway by investigating the formation of the ferroelectric Pca21 phase via X2−{X}_{2}^{-} displacement and symmetry-allowed phonon mode instability. Our results reveal that applying tensile strain regardless of direction enhances the X2−{X}_{2}^{-} displacement and induces instabilities in the polar and antipolar modes, causing the P42/nmc phase to collapse into Pbcn or Aba2, depending on the strain direction. Emergent polar and antipolar mode displacements at the primary transition couple to X2−{X}_{2}^{-}, lowering the trilinear-coupling barrier and stabilizing Pca21. Although the X2−{X}_{2}^{-} mode alone makes only a minor contribution, its coupling with other distortion modes governs the entire energy landscape by driving the Landau coefficients to negative values, initiating the kinetic transition pathway toward the Pca21 phase. This fundamental paradigm shift toward a mechanism governed by the X2−{X}_{2}^{-} displacement provides a way to control the ferroelectric phase fraction in polycrystalline films under various substrate conditions via X2−{X}_{2}^{-} engineering, paving the way for a foundation for the practical realization of ferroelectricity in device applications.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"53 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147496816","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

Imaging of altermagnetic domains in orthoferrite DyFeO3 using electric field-induced nonreciprocal directional dichroism 用电场诱导的非互反定向二色性成像正交铁氧体DyFeO3的互磁畴

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-03-13 DOI: 10.1038/s41535-026-00861-z

Koh Kobayashi, Takeshi Hayashida, Tsuyoshi Kimura

{"title":"Imaging of altermagnetic domains in orthoferrite DyFeO3 using electric field-induced nonreciprocal directional dichroism","authors":"Koh Kobayashi, Takeshi Hayashida, Tsuyoshi Kimura","doi":"10.1038/s41535-026-00861-z","DOIUrl":"https://doi.org/10.1038/s41535-026-00861-z","url":null,"abstract":"Rare-earth orthoferrites (RFeO3, R: rare-earth ions) have long been studied for their unique antiferromagnetic properties arising from the interplay between two magnetic sublattices, formed by Fe³⁺ and R³⁺ ions. From a modern perspective, the antiferromagnetic order in RFeO₃ can be classified as altermagnetic, characterized by macroscopic time-reversal symmetry breaking without net magnetization. In this study, we focus on the altermagnetic Γ₁ phase of DyFeO₃, which exhibits time-reversal symmetry breaking while spontaneous magnetization is forbidden. We successfully visualize altermagnetic domains in this phase using electric field-induced nonreciprocal directional dichroism (NDD), in which the optical absorption changes with the applied electric field. We further demonstrate that the domain structure is influenced by an external magnetic field, mediated by piezomagnetic coupling through internal strain. Our results establish electric field-induced NDD as a powerful tool for probing altermagnetic domain structures, where conventional magneto-optical techniques such as the Faraday or Kerr effect are ineffective.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"54 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147454745","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