Article
Physics, Multidisciplinary
O. Tanaka, Y. Mizukami, R. Harasawa, K. Hashimoto, K. Hwang, N. Kurita, H. Tanaka, S. Fujimoto, Y. Matsuda, E-G Moon, T. Shibauchi
Summary: By measuring the heat capacity of alpha-RuCl3 under different magnetic field directions, this study reveals strongly angle-dependent low-energy excitations in the material. These findings are consistent with the characteristics of itinerant Majorana fermions in the Kitaev model. Furthermore, the changes in edge transport correspond to the opening and closing of the bulk gap according to the magnetic field direction, and the absence of the quantum thermal Hall effect at higher magnetic fields suggests a nematic quantum spin liquid state with two-fold rotational symmetry.
Article
Physics, Multidisciplinary
E. Lefrancois, G. Grissonnanche, J. Baglo, P. Lampen-Kelley, J. -Q. Yan, C. Balz, D. Mandrus, S. E. Nagler, S. Kim, Young-June Kim, N. Doiron-Leyraud, Louis Taillefer
Summary: RuCl3 undergoes a transition to a state with antiferromagnetic order below a temperature of about 7 K, but this order can be suppressed by applying an external magnetic field. The existence of a quantum spin liquid phase just above a certain magnetic field is still uncertain, but recent observations suggest the presence of itinerant Majorana fermions.
Article
Materials Science, Multidisciplinary
Alexandros Metavitsiadis, Wolfram Brenig
Summary: The study focuses on the self-localization and possible delocalization mechanisms of the Kitaev spin-1/2 ladder model. It is found that the influence of magnetic fields on the system is achieved through flux mobility, with flux mobility being the key to entering a delocalized state.
Article
Materials Science, Multidisciplinary
Emily Z. Zhang, Reja H. Wilke, Yong Baek Kim
Summary: There has been significant interest in finding a Kitaev quantum spin liquid state in magnets with bond-dependent interactions. The observation of a half-quantized thermal Hall conductivity in alpha-RuCl3 in the presence of a magnetic field has generated excitement as it could indicate a field-induced chiral spin liquid. However, recent experiments propose a different interpretation, suggesting that topological magnons in the field-polarized state are responsible for the nonquantized thermal Hall conductivity. In this work, three theoretical models with large Kitaev interactions are used to analyze the crossover behavior between the spin excitation continuum and topological magnons at finite temperature.
Article
Materials Science, Multidisciplinary
Kexin Feng, Aysel Shiralieva, Natalia B. Perkins
Summary: It has been found that phonon dynamics can serve as an indirect probe of spin fractionalization, and sound attenuation measurements can be used to characterize and identify the Kitaev quantum spin liquid. On the hyperhoneycomb lattice, sound attenuation exhibits a characteristic angular dependence.
Article
Multidisciplinary Sciences
Kyusung Hwang, Ara Go, Ji Heon Seong, Takasada Shibauchi, Eun-Gook Moon
Summary: This paper proposes a concrete way to identify the non-abelian Kitaev quantum spin liquid by magnetic field angle dependence, providing criteria for such a state for future experiments.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Pavel A. Maksimov
Summary: This study investigates the field-induced phase transitions of BaCo2(AsO4)2, a candidate for the Kitaev honeycomb model, using numerical methods. The observed sequence of steplike transitions in magnetic field is realized in the phase diagram of the minimal model. Interestingly, an intermediate up-up-down plateau phase is stabilized near a double-zigzag-zigzag phase boundary.
Article
Physics, Fluids & Plasmas
Owen Bradley, Jaan Oitmaa, Diptiman Sen, Rajiv R. P. Singh
Summary: This study examines the thermodynamic behavior of modified spin-S Kitaev models, finding distinct properties for half-odd-integer spins and integer spins. Various thermodynamic properties are explored through transfer matrix methods, high-temperature expansions, and Monte Carlo simulations for ferromagnetic and antiferromagnetic models with spin S = 1 and S = 2. The results reveal a range of behaviors, including finite, critical, or exponential correlation lengths as temperature approaches zero, as well as differences in the saturation of Z(2) flux variables among different models.
Article
Materials Science, Multidisciplinary
Hengdi Zhao, Bing Hu, Feng Ye, Minhyea Lee, Pedro Schlottmann, Gang Cao
Summary: The study reports the crystal structure and mixed valence state of the synthesized honeycomb iridate NaxIrO3, suggesting its potential as a Mott insulator with interesting physical behaviors, possibly approaching a Kitaev spin liquid state.
Article
Materials Science, Multidisciplinary
Chanhyeon Lee, Suheon Lee, Youngsu Choi, C. Wang, H. Luetkens, T. Shiroka, Zeehoon Jang, Young-Gui Yoon, Kwang-Yong Choi
Summary: We used various measurements, including magnetic susceptibility, muon-spin relaxation, and nuclear magnetic resonance, to study the spin dynamics of the quantum spin liquid candidate H3LiIr2O6. We identified two characteristic temperatures, Tg = 110 K and T* = 26 K, through analysis of the relaxation rates. Below Tg, there were distinct components of slower relaxation rate governed by gapped excitations and faster relaxation rate related to gapless excitations. We observed divergent magnetic susceptibility, power-law dependence of relaxation rate on temperature, and weakly activated behavior, indicating the coexistence of a disordered spin-liquid state and spin singlets with distributed gaps.
Article
Physics, Multidisciplinary
Wen-Han Kao, Johannes Knolle, Gabor B. Halasz, Roderich Moessner, Natalia B. Perkins
Summary: In this study, the introduction of random vacancies in the Kitaev model is shown to lead to a power-law upturn in specific heat measurements of H3LiIr2O6, and new insights into the system's response are proposed. The origin and nature of vacancies have minimal impact on the significant accumulation of low-energy Majorana modes, which can be readily detected.
Article
Physics, Multidisciplinary
Xiaoxue Zhao, Kejing Ran, Jinghui Wang, Song Bao, Yanyan Shangguan, Zhentao Huang, Junbo Liao, Bo Zhang, Shufan Cheng, Hao Xu, Wei Wang, Zhao-Yang Dong, Siqin Meng, Zhilun Lu, Shin-ichiro Yano, Shun-Li Yu, Jian-Xin Li, Jinsheng Wen
Summary: Experimental study on the evolution of magnetic excitations of α-RuCl3 under an in-plane magnetic field reveals the emergence of a pure QSL state near the critical field. This suggests that an in-plane magnetic field can drive α-RuCl3 into the long-sought QSL state.
CHINESE PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
A. Metavitsiadis, W. Natori, J. Knolle, W. Brenig
Summary: Emergent excitation continua in frustrated magnets are a fingerprint of fractionalization, characteristic of quantum spin-liquid states. Recent evidence from Raman scattering for a coupling between such continua and lattice degrees of freedom in putative Kitaev magnets may provide insight into the nature of the fractionalized quasiparticles. The renormalization of optical phonons coupled to the underlying Z2 quantum spin liquid is studied, revealing that phonon line shapes acquire an asymmetry due to the dispersion of the Majorana continuum and the Fano effect. The increase of phonon lifetimes with temperature is attributed to thermal blocking of phase space. Optical phonon renormalization shows little sensitivity to thermally excited gauge fluxes and external magnetic fields.
Article
Multidisciplinary Sciences
Shang-Shun Zhang, Gabor B. Halasz, Cristian D. Batista
Summary: This study reveals the existence of a gapped spin liquid phase in the antiferromagnetic Kitaev model at intermediate magnetic fields through the use of a variational approach. Furthermore, the characteristics and critical behaviors of this phase are investigated, providing valuable insights into the nature of the spin liquid.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Wen-Han Kao, Natalia B. Perkins
Summary: This study explores the response of the Kitaev QSL to various forms of disorder, revealing that quenched disorder can lead to Anderson localization of Majorana fermions and the appearance of Lifshitz tails. Disorder effects on low-energy Majorana fermion modes can be detected in thermal transport, with Z2 fluxes becoming thermally excited at finite temperatures, dominating as a source of disorder at high temperatures. The energy spectrum and thermal transport properties of disordered Kitaev QSL strongly depend on the character of disorder, with site disorder and bond randomness suppressing longitudinal thermal conductivity while low-energy localization is stronger with site disorder.
Article
Chemistry, Physical
William Lafargue-Dit-Hauret, Camille Latouche, Stephane Jobic
Summary: This theoretical investigation focused on the ab initio determination of redox potentials of a dopant in a host lattice. The study used first-principles methods with the SCAN functional on doped materials in a supercell approach, particularly focusing on 3d transition metal dopants in rutile TiO2. The stability of point defects at different charge states and the calculation of associated charge transition levels in the material's band gap were discussed.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Jonathan Gaudet, Hung-Yu Yang, Santu Baidya, Baozhu Lu, Guangyong Xu, Yang Zhao, Jose A. Rodriguez-Rivera, Christina M. Hoffmann, David E. Graf, Darius H. Torchinsky, Predrag Nikolic, David Vanderbilt, Fazel Tafti, Collin L. Broholm
Summary: In NdAlSi, Weyl fermions mediate a helical incommensurate spin density wave, serving as a rare example of Weyl-mediated collective phenomena. This material demonstrates unique electronic properties of Weyl semimetals and reveals collective magnetism associated with Weyl fermions through techniques such as neutron diffraction.
Article
Multidisciplinary Sciences
Hung-Yu Yang, Xiaohan Yao, Vincent Plisson, Shirin Mozaffari, Jan P. Scheifers, Aikaterini Flessa Savvidou, Eun Sang Choi, Gregory T. McCandless, Mathieu F. Padlewski, Carsten Putzke, Philip J. W. Moll, Julia Y. Chan, Luis Balicas, Kenneth S. Burch, Fazel Tafti
Summary: Experimental evidence is presented for a coupled electron-phonon liquid in NbGe2, where phonons and electrons form a coupled non-equilibrium state characterized by the conservation of total momentum and hydrodynamic transport.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Inorganic & Nuclear
Emiliano Martinez-Vollbert, Charles Ciambrone, William Lafargue-Dit-Hauret, Camille Latouche, Frederique Loiseau, Pierre-Henri Lanoe
Summary: In this study, a new family of cationic iridium(III) complexes with modified emission properties and photoluminescence quantum yield were investigated by introducing different substituents. A switch of the lowest triplet excited state was observed. The experimental and theoretical results showed good agreement, demonstrating the potential of these complexes as emitting materials.
INORGANIC CHEMISTRY
(2022)
Article
Physics, Condensed Matter
William Lafargue-Dit-Hauret, Xavier Rocquefelte
Summary: This study investigated the electronic and magnetic properties of two oxohalide compounds, Cu-3(SeO3)(2)Cl-2 and Cu-3(TeO3)(2)Br-2, using density functional theory (DFT). The involvement of Se and Te lone pairs in the long-range magnetic order was revealed, providing important information for the chemical design of original magnetic systems.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
William Lafargue-Dit-Hauret, Camille Latouche, Mathieu Allix, Bruno Viana, Stephane Jobic
Summary: This article presents the first comprehensive ab initio computational study on intrinsic point defects in Sr4Al14O25. It reveals that most point defects have high formation energy under different oxygen environments, except for oxygen vacancies in low oxygen conditions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Andreas Kourtellaris, William Lafargue-Dit-Houret, Florian Massuyeau, Camille Latouche, Anastasios J. Tasiopoulos, Helene Serier-Brault
Summary: An initial investigation on the modulation of the thermometric properties of metal-organic frameworks (MOFs) through targeted structural alterations using post-synthesis modification method is reported. The study reveals that altering terminal and chelating ligands can significantly affect the sensitivity and operating temperature range of MOFs.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Chemistry, Physical
Didier Begue, William Lafargue-Dit-Hauret, Alain Dargelos, Curt Wentrup
Summary: This study examines the chemical properties and interconversion among fulminic and cyanic acids. The results show that formylnitrene can be isomerized to HNCO through thermal or photochemical reactions, and fulminic acid can generate HNCO via the isomerization of formylnitrene.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Multidisciplinary Sciences
Gang Qiu, Hung-Yu Yang, Lunhui Hu, Huairuo Zhang, Chih-Yen Chen, Yanfeng Lyu, Christopher Eckberg, Peng Deng, Sergiy Krylyuk, Albert V. Davydov, Ruixing Zhang, Kang L. Wang
Summary: In this study, van der Waals Josephson junctions made with iron-based superconductor Fe(Te,Se) were fabricated, and the global device-level transport signatures of interfacial ferromagnetism emerging with superconducting states were reported for the first time. Additionally, a stochastic field-free superconducting diode effect was observed, confirming the spontaneous time-reversal symmetry breaking.
NATURE COMMUNICATIONS
(2023)
Review
Chemistry, Multidisciplinary
Gang Qiu, Hung-Yu Yang, Su Kong Chong, Yang Cheng, Lixuan Tai, Kang L. Wang
Summary: Magnetic topological insulators (MTIs) are materials that combine topological band structures with magnetism, offering new opportunities for technological advancements. This paper reviews the mainstream MTI material platforms and highlights recent developments in modulating topological properties in MTIs through various means. The manipulation of topological phases in MTIs provides an exciting avenue for fundamental research and practical applications.
Article
Materials Science, Multidisciplinary
Xavier Rocquefelte, Mirta Herak, Atsushi Miyake, William Lafargue-Dit-Hauret, Helmuth Berger, Masashi Tokunaga, Andres Saul
Summary: We conducted a combined theoretical and experimental investigation on the exotic magnetic properties of the low-dimensional SeCuO3 system, and observed different quantum dynamics at the two Cu(1) and Cu(2) sites. Through first-principles calculations based on density functional theory, we decomposed the magnetic structure into two subsystems consisting of strongly antiferromagnetically coupled Cu(1) singlet state dimers and weak antiferromagnetic Cu(2) spin chains, with weak ferromagnetic interactions causing magnetic frustration. Our model successfully reproduced magnetic susceptibility and torque magnetometry measurements. Furthermore, high-magnetic-field experiments and density-matrix renormalization-group simulations revealed a half-magnetization plateau at 40-45 T associated with the polarization of the Cu(2) spin chains, while the Cu(1) dimers were expected to reach the triplet state at 210-220 T.
Article
Mathematics, Interdisciplinary Applications
William Lafargue-Dit-Hauret, Xavier Rocquefelte
Summary: In this study, the structural, electronic, and magnetic properties of the Cu2OX2 compounds were investigated theoretically. The study focused on the calculation of J exchange couplings and the impact of chemical pressure on magnetic interactions. It was found that chemical pressure is an effective key factor for achieving room-temperature multiferroicity.
Article
Materials Science, Multidisciplinary
Yue Sun, Changmin Lee, Hung-Yu Yang, Darius H. Torchinsky, Fazel Tafti, Joseph Orenstein
Summary: The study reports full vector mapping of local magnetization in CeAlSi, a Weyl semimetal with broken inversion and time-reversal symmetries. The vector maps reveal unexpected features within domains and at their boundaries, including two types of domain walls with distinct topology and the splitting of easy axes into an octet below the magnetic transition as temperature decreases. These phenomena are ultimately attributed to the noncollinear magnetic structure of CeAlSi.
Article
Materials Science, Multidisciplinary
Hung-Yu Yang, Bahadur Singh, Jonathan Gaudet, Baozhu Lu, Cheng-Yi Huang, Wei-Chi Chiu, Shin-Ming Huang, Baokai Wang, Faranak Bahrami, Bochao Xu, Jacob Franklin, Ilya Sochnikov, David E. Graf, Guangyong Xu, Yang Zhao, Christina M. Hoffman, Hsin Lin, Darius H. Torchinsky, Collin L. Broholm, Arun Bansil, Fazel Tafti
Summary: Research on novel electromagnetic responses such as the anomalous Hall effect in ferromagnetic Weyl semimetals shows promise. CeAlSi, a FM-WSM material, stands out for its noncentrosymmetric lattice, noncollinear FM ordering, and novel AHE that is anisotropic between the easy and hard magnetic axes. This material also exhibits large FM domains, offering potential for exploring device applications and the interplay between Weyl nodes and FM domain walls.
Article
Quantum Science & Technology
Bochao Xu, Jacob Franklin, Amani Jayacody, Hung-Yu Yang, Fazel Tafti, Ilya Sochnikov
Summary: The study used a scanning superconducting quantum interference device microscope to observe the magnetic properties of CeAlSi, a noncentrosymmetric ferromagnetic Weyl semimetal candidate, revealing metastable magnetic domains with emergent and exotic characteristics. The heterogeneity of the two types of domains is mainly due to magnetoelastic or magnetostriction effects, and these domains can be manipulated or stabilized with picometer-level lattice strains.
ADVANCED QUANTUM TECHNOLOGIES
(2021)
