npj Quantum Materials最新文献_第8页

Unraveling quantum dephasing of nitrogen-vacancy center ensembles in diamond 金刚石中氮空位中心系综的量子脱相

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-03-12 DOI: 10.1038/s41535-026-00869-5

Jixing Zhang, Cheuk Kit Cheung, Michael Kübler, Magnus Benke, Mathis Brossaud, Yihua Wang, Andrej Denisenko, Ruoming Peng, Jens Anders, Emilio Corcione, Cristina Tarín Sauer, Andrew M. Edmonds, Matthew Markham, Kazuo Nakamura, Hitoshi Sumiya, Shinobu Onoda, Junichi Isoya, Chen Zhang, Jörg Wrachtrup

{"title":"Unraveling quantum dephasing of nitrogen-vacancy center ensembles in diamond","authors":"Jixing Zhang, Cheuk Kit Cheung, Michael Kübler, Magnus Benke, Mathis Brossaud, Yihua Wang, Andrej Denisenko, Ruoming Peng, Jens Anders, Emilio Corcione, Cristina Tarín Sauer, Andrew M. Edmonds, Matthew Markham, Kazuo Nakamura, Hitoshi Sumiya, Shinobu Onoda, Junichi Isoya, Chen Zhang, Jörg Wrachtrup","doi":"10.1038/s41535-026-00869-5","DOIUrl":"https://doi.org/10.1038/s41535-026-00869-5","url":null,"abstract":"Nitrogen-vacancy (NV) center ensembles in diamond are one of the most promising solid-state quantum platforms for various sensing applications. Achieving ultimate sensitivity requires simultaneously long spin dephasing times (({T}_{2}^{* })) and high NV center concentrations. In this work, we propose a systematic measurement approach to quantify the electron spin dephasing in NV center ensembles and analyze the contributions of various sources to the dephasing time, including NV-NV interactions, strain and electric field distributions, 13C nuclear spins, and P1 electron spins. Our method is validated using a series of high-performance diamond samples, providing a comprehensive understanding of dephasing mechanisms and revealing correlations between NV concentration and different dephasing sources. Building on these insights, we outline strategies to further enhance the achievable sensitivity for DC magnetic field measurements.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"43 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147394035","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 of the Kitaev model candidate RuBr3 Kitaev模型候选者RuBr3的磁激励

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-03-11 DOI: 10.1038/s41535-026-00868-6

Kazuhiro Nawa, Yoshinori Imai, Maiko Kofu, Richard Mole, Hideyuki Fujihara, Takumi Hiraoka, Ryo Murasaki, Pharit Piyawongwatthana, Daisuke Okuyama, Hirotada Gotou, Kenya Ohgushi, Taku J. Sato

{"title":"Magnetic excitations of the Kitaev model candidate RuBr3","authors":"Kazuhiro Nawa, Yoshinori Imai, Maiko Kofu, Richard Mole, Hideyuki Fujihara, Takumi Hiraoka, Ryo Murasaki, Pharit Piyawongwatthana, Daisuke Okuyama, Hirotada Gotou, Kenya Ohgushi, Taku J. Sato","doi":"10.1038/s41535-026-00868-6","DOIUrl":"https://doi.org/10.1038/s41535-026-00868-6","url":null,"abstract":"The Kitaev model, which consists of bond-dependent Ising interactions on the honeycomb plane, is known as a promising model for realising a spin liquid in the exact ground state. Since bond-dependent Ising interactions are induced by orbital exchange processes via ligand ions, it is important to reveal the effect of ligand ions on the formation of bond-dependent Ising interactions experimentally. In this study, we performed powder inelastic neutron scattering on RuBr3 with a layered honeycomb structure, which is isostructural to the low-temperature structure of α-RuCl3. Strongly dispersive magnetic modes were observed near the centre of the antiferromagnetic zone below TN. With increasing temperature, the spectral weight remains near the centre of the antiferromagnetic zone just above TN, whereas it shifts to the Γ point at 3TN. Strong dispersion indicates that antiferromagnetic interactions that stabilise the zigzag antiferromagnetic order, namely, nearest-neighbour symmetric off-diagonal or third-neighbour isotropic magnetic interactions, are comparable to or even stronger than ferromagnetic Kitaev interactions, and drive the ground state of RuBr3 away from the ideal ferromagnetic Kitaev spin liquid state.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"411 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147394040","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

Anomalous Landau levels and quantum oscillation in rotation-invariant insulators 旋转不变绝缘体中的异常朗道能级和量子振荡

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-03-05 DOI: 10.1038/s41535-026-00867-7

Jianlong Fu, Chun Yu Weng, Hoi Chun Po

引用次数: 0

Strain-tuned ferroelectric transitions in HfO2: role of ({X}_{2}^{-}) mode in ferroelectric instabilities HfO2中应变调谐铁电跃迁：({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 : 2026-03-03 DOI: 10.1038/s41535-025-00841-9

Ilyoung Lee, Wontae Lee, Jaejun Yu

{"title":"Strain-tuned ferroelectric transitions in HfO2: role of ({X}_{2}^{-}) mode in ferroelectric instabilities","authors":"Ilyoung Lee, Wontae Lee, Jaejun Yu","doi":"10.1038/s41535-025-00841-9","DOIUrl":"https://doi.org/10.1038/s41535-025-00841-9","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 ({X}_{2}^{-}) displacement and symmetry-allowed phonon mode instability. Our results reveal that applying tensile strain regardless of direction enhances the ({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 ({X}_{2}^{-}), lowering the trilinear-coupling barrier and stabilizing Pca21. Although the ({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 ({X}_{2}^{-}) displacement provides a way to control the ferroelectric phase fraction in polycrystalline films under various substrate conditions via ({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":"61 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147346812","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

A wide-range topological thermometer with Ta2Pd3Te5: from power-law response to application prospects Ta2Pd3Te5宽范围拓扑温度计：从幂律响应到应用前景

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-02-20 DOI: 10.1038/s41535-026-00866-8

Yupeng Li, Anqi Wang, Senyang Pan, Dayu Yan, Guang Yang, Xingchen Guo, Yu Hong, Zhiyuan Zhang, Ziwei Dou, Guangtong Liu, Fanming Qu, Zhijun Wang, Tian Qian, Jinglei Zhang, Youguo Shi, Li Lu, Jie Shen

{"title":"A wide-range topological thermometer with Ta2Pd3Te5: from power-law response to application prospects","authors":"Yupeng Li, Anqi Wang, Senyang Pan, Dayu Yan, Guang Yang, Xingchen Guo, Yu Hong, Zhiyuan Zhang, Ziwei Dou, Guangtong Liu, Fanming Qu, Zhijun Wang, Tian Qian, Jinglei Zhang, Youguo Shi, Li Lu, Jie Shen","doi":"10.1038/s41535-026-00866-8","DOIUrl":"https://doi.org/10.1038/s41535-026-00866-8","url":null,"abstract":"In recent decades, there has been a persistent pursuit of applications for surface/edge states in topological systems, driven by their dissipationless transport effects. This work demonstrates the remarkable properties of the topological material Ta 2 Pd 3 Te 5 , as a thermometer. At low temperatures, it shows a power-law correlation in temperature-dependent resistance, while behaving like a semiconductor at high temperatures. This dual behavior effectively mitigates the issue of infinite resistance in semiconductor thermometers at ultra-low temperatures, making it ideal for millikelvin-range refrigerators. Through chemical doping, thickness adjustment, and gate voltage control, its performance can be finely tuned, and can also enable micron-scale local temperature measurement from millikelvin to room temperature. Furthermore, this thermometer exhibits excellent temperature sensitivity and resolution, and can be fine-tuned to show small magnetoresistance. In summary, the Ta 2 Pd 3 Te 5 -based thermometer, also referred to as a topological thermometer, demonstrates considerable potential for broad-temperature-range detection and merits further investigation and optimization.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"8 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146223204","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

Quantum theory of magnetic octupole in periodic crystals and application to d-wave altermagnets 周期晶体中磁八极子的量子理论及其在d波交替磁体中的应用

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-02-20 DOI: 10.1038/s41535-026-00865-9

Takumi Sato, Satoru Hayami

{"title":"Quantum theory of magnetic octupole in periodic crystals and application to d-wave altermagnets","authors":"Takumi Sato, Satoru Hayami","doi":"10.1038/s41535-026-00865-9","DOIUrl":"https://doi.org/10.1038/s41535-026-00865-9","url":null,"abstract":"Magnetic multipoles have been recognized as order parameters characterizing magnetic structure in solids. Recently, magnetic octupoles have been proposed as the order parameters of time-reversal-symmetry-breaking centrosymmetric antiferromagnets exhibiting nonrelativistic spin splitting, which is referred to as “altermagnet”. However, a gauge-invariant formulation of magnetic octupoles in crystalline solids remains elusive. Here, we present a gauge-invariant expression of spin magnetic octupoles in periodic crystals based on quantum mechanics and thermodynamics, which can be used to quantitatively characterize time-reversal-symmetry-breaking antiferromagnets, including d -wave altermagnets. The allowed physical response tensors are classified beyond symmetry considerations, and direct relationships are established for some of them in insulators at zero temperature. Furthermore, our expression reveals a contribution from an anisotropic magnetic dipole, which has the same symmetry as conventional spin and orbital magnetic dipoles but carries no net magnetization. We discuss the relation between the anisotropic magnetic dipole and the anomalous Hall effect.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"1 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146223202","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

Optical phonons as a testing ground for spin group symmetries 光学声子作为自旋群对称性的试验场

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-02-17 DOI: 10.1038/s41535-026-00857-9

F. Schilberth, M. Kondákor, D. Ukolov, A. Pawbake, K. Vasin, O. Ercem, L. Prodan, V. Tsurkan, A. A. Tsirlin, C. Faugeras, P. Lemmens, K. Penc, I. Kézsmárki, S. Bordács, J. Deisenhofer

{"title":"Optical phonons as a testing ground for spin group symmetries","authors":"F. Schilberth, M. Kondákor, D. Ukolov, A. Pawbake, K. Vasin, O. Ercem, L. Prodan, V. Tsurkan, A. A. Tsirlin, C. Faugeras, P. Lemmens, K. Penc, I. Kézsmárki, S. Bordács, J. Deisenhofer","doi":"10.1038/s41535-026-00857-9","DOIUrl":"https://doi.org/10.1038/s41535-026-00857-9","url":null,"abstract":"Lattice vibrations are highly sensitive to crystal symmetries and their changes across phase transitions. The latter can modify irreducible (co)representations and corresponding infrared and Raman selection rules of phonons. This concept is established for relativistic magnetic point groups, simultaneously transforming spatial and spin coordinates. However, in altermagnets described by non-relativistic spin groups with disjunct symmetry operations for both vector spaces, the phonon selection rules have remained unexplored. Here, we present a detailed study of the infrared- and Raman-active modes in the collinear antiferromagnet and altermagnet candidate Co 2 Mo 3 O 8 . Comparing to ab initio calculations accurately capturing the eigenfrequencies, we identify all expected phonon modes at room temperature and deduce their selection rules using both symmetry approaches. Importantly, we observe the change of selection rules upon antiferromagnetic ordering, agreeing with the relativistic symmetry approach, while the spin group formalism predicts no changes. Therefore, optical phonons sensing the symmetry of the magnetic order can reveal if relevant magnon-phonon coupling is compatible with the spin-group approach or not.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"6 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146210081","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

Superconductivity induced by spin-orbit coupling in a two-valley ferromagnet 双谷铁磁体中自旋轨道耦合诱导的超导性

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-02-13 DOI: 10.1038/s41535-026-00864-w

Zachary M. Raines, Andrey V. Chubukov

引用次数: 0

The influence of phonon symmetry and electronic structure on the electron-phonon coupling momentum dependence in cuprates 铜酸盐中声子对称性和电子结构对电子-声子耦合动量依赖的影响

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-02-13 DOI: 10.1038/s41535-026-00863-x

Maryia Zinouyeva, Rolf Heid, Giacomo Merzoni, Riccardo Arpaia, Nikolai Andreev, Marco Biagi, Nicholas B. Brookes, Daniele Di Castro, Alexei Kalaboukhov, Kurt Kummer, Floriana Lombardi, Leonardo Martinelli, Francesco Rosa, Matteo Rossi, Flora Yakhou-Harris, Lucio Braicovich, Marco Moretti, Paolo G. Radaelli, Giacomo Ghiringhelli

{"title":"The influence of phonon symmetry and electronic structure on the electron-phonon coupling momentum dependence in cuprates","authors":"Maryia Zinouyeva, Rolf Heid, Giacomo Merzoni, Riccardo Arpaia, Nikolai Andreev, Marco Biagi, Nicholas B. Brookes, Daniele Di Castro, Alexei Kalaboukhov, Kurt Kummer, Floriana Lombardi, Leonardo Martinelli, Francesco Rosa, Matteo Rossi, Flora Yakhou-Harris, Lucio Braicovich, Marco Moretti, Paolo G. Radaelli, Giacomo Ghiringhelli","doi":"10.1038/s41535-026-00863-x","DOIUrl":"https://doi.org/10.1038/s41535-026-00863-x","url":null,"abstract":"The experimental determination of the magnitude and momentum dependence of electron-phonon coupling (EPC) is an outstanding problem in condensed matter physics. The intensity of phonon peaks in Resonant Inelastic X-ray Scattering (RIXS) spectra can be related to the underlying EPC strength under significant approximations whose validity deserves careful verification. We measured the Cu L3 RIXS phonon intensity as a function of incident photon energy and momentum transfer in several layered cuprates. For CaCuO2, La2−xSrxCuO4+δ, and YBa2Cu3O6, using a generally accepted theoretical model, we quantitatively estimate the EPC for the bond-stretching mode along the high-symmetry directions (ζ,0) and (ζ,ζ), and as a function of the azimuthal angle φ at fixed q∥. We compare our results with theoretical predictions and find that the q∥-dependence of the phonon RIXS intensity can be largely ascribed to the phonon symmetry. However, a more satisfactory prediction of the experimental results requires an accurate description of the electronic structure close to the Fermi level. Our extensive investigation indicates that Cu L3 RIXS can reliably determine the momentum dependence of EPC for the bond-stretching modes of cuprates. Moreover, the large experimental basis provided here constitutes a stringent test for advanced theoretical predictions on the EPC.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"40 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146196761","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

Vanishing ordered moment in the frustrated triangular lattice antiferromagnet CuNdO2 受挫三角晶格反铁磁体CuNdO2的消失有序矩

IF 5.7 1区物理与天体物理

npj Quantum Materials Pub Date : 2026-02-11 DOI: 10.1038/s41535-026-00854-y

Jonathan Gaudet, Dalmau Reig-i-Plessis, Bogeng Wen, Thomas J. Hicken, Jonas A. Krieger, Jan Peter Embs, Hubertus Luetkens, Adam A. Aczel, Stuart A. Calder, Matthew B. Stone, Hae-Young Kee, Alannah M. Hallas

{"title":"Vanishing ordered moment in the frustrated triangular lattice antiferromagnet CuNdO2","authors":"Jonathan Gaudet, Dalmau Reig-i-Plessis, Bogeng Wen, Thomas J. Hicken, Jonas A. Krieger, Jan Peter Embs, Hubertus Luetkens, Adam A. Aczel, Stuart A. Calder, Matthew B. Stone, Hae-Young Kee, Alannah M. Hallas","doi":"10.1038/s41535-026-00854-y","DOIUrl":"https://doi.org/10.1038/s41535-026-00854-y","url":null,"abstract":"We investigate the magnetic ground state of CuNdO2, which is a delafossite with a triangular lattice of magnetic Nd3+ ions that are well separated by non-magnetic Cu spacer layers. From inelastic neutron scattering measurements of the crystal electric field, we determine the strong Ising character of the pseudo-spin 1/2 Nd3+ moments. Magnetic susceptibility and heat capacity measurements reveal the onset of long-range antiferromagnetic order at TN = 0.78 K. While the magnetic transition is definitively observed with muon spin relaxation, accompanied by the formation of a weakly dispersing spin wave excitation, no dipole-ordered moment is detected with neutron diffraction. We show that the apparent absence of a dipolar ordered moment is a consequence of the dominant Ising character of the antiferromagnetically coupled Nd3+ moments, which experience extreme frustration on the triangular lattice. Consequently, the frustration in CuNdO2 is relieved through in-plane ordering of the substantially smaller perpendicular component of the Nd3+ moments into a 120° structure, with a nearly vanishing ordered moment.","PeriodicalId":19283,"journal":{"name":"npj Quantum Materials","volume":"95 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146152278","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