arXiv: Strongly Correlated Electrons最新文献_第3页

Charge fractionalization beyond the Luttinger liquid paradigm: An analytical consideration 超越Luttinger液体范式的电荷分馏:一种分析考虑

arXiv: Strongly Correlated Electrons Pub Date : 2020-12-01 DOI: 10.1103/PhysRevB.103.195148

A. Dontsov, A. Dmitriev

引用次数: 0

Magnetic ground state of the one-dimensional ferromagnetic chain compoundsM(NCS)2(thiourea)2(M=Ni,Co) 一维铁磁链化合物dsm (NCS)2(硫脲)2(M=Ni,Co)的磁基态

arXiv: Strongly Correlated Electrons Pub Date : 2020-12-01 DOI: 10.1103/PHYSREVMATERIALS.5.034401

S. Curley, R. Scatena, R. C. Williams, P. Goddard, P. Macchi, T. J. Hicken, T. Lancaster, F. Xiao, S. Blundell, V. Zapf, J. Eckert, E. Krenkel, J. Villa, M. Rhodehouse, J. Manson

{"title":"Magnetic ground state of the one-dimensional ferromagnetic chain compoundsM(NCS)2(thiourea)2(M=Ni,Co)","authors":"S. Curley, R. Scatena, R. C. Williams, P. Goddard, P. Macchi, T. J. Hicken, T. Lancaster, F. Xiao, S. Blundell, V. Zapf, J. Eckert, E. Krenkel, J. Villa, M. Rhodehouse, J. Manson","doi":"10.1103/PHYSREVMATERIALS.5.034401","DOIUrl":"https://doi.org/10.1103/PHYSREVMATERIALS.5.034401","url":null,"abstract":"The magnetic properties of the two isostructural molecule-based magnets, Ni(NCS)$_{2}$(thiourea)$_{2}$, $S$ = 1, [thiourea = SC(NH$_2$)$_2$] and Co(NCS)$_{2}$(thiourea)$_{2}$, $S$ = 3/2, are characterised using several techniques in order to rationalise their relationship with structural parameters and ascertain magnetic changes caused by substitution of the spin. Zero-field heat capacity and muon-spin relaxation measurements reveal low-temperature long-range ordering in both compounds, in addition to Ising-like ($D < 0$) single-ion anisotropy ($D_{rm{Co}} sim$ -100 K, $D_{rm{Ni}} sim$ -10 K). Crystal and electronic structure, combined with DC-field magnetometry, affirm highly quasi-one-dimensional behaviour, with ferromagnetic intrachain exchange interactions $J_{rm{Co}}approx+4$ K and $J_{rm{Ni}}sim+100$ K and weak antiferromagnetic interchain exchange, on the order of $J'$ $sim-0.1$ K. Electron charge and spin-density mapping reveals through-space exchange as a mechanism to explain the large discrepancy in $J$-values despite, from a structural perspective, the highly similar exchange pathways in both materials. Both species can be compared to the similar compounds $M$Cl$_2$(thiourea)$_4$, $M$ = Ni(II) (DTN) and Co(II) (DTC), where DTN is know to harbour two magnetic field-induced quantum critical points. Direct comparison of DTN and DTC with the compounds studied here shows that substituting the halide Cl$^-$ ion, for the NCS$^-$ ion, results in a dramatic change in both the structural and magnetic properties.","PeriodicalId":8511,"journal":{"name":"arXiv: Strongly Correlated Electrons","volume":"49 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91431623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

First-principles investigation of magnetic and transport properties in hole-doped shandite compounds Co3InxSn2−xS2 空穴掺杂山德岩化合物Co3InxSn2−xS2磁性和输运性质的第一性原理研究

arXiv: Strongly Correlated Electrons Pub Date : 2020-11-30 DOI: 10.1103/PhysRevB.103.205112

Y. Yanagi, J. Ikeda, K. Fujiwara, K. Nomura, A. Tsukazaki, Michi-To Suzuki

引用次数: 8

Spin Seebeck effect in nonmagnetic excitonic insulators 非磁性激子绝缘体中的自旋塞贝克效应

arXiv: Strongly Correlated Electrons Pub Date : 2020-11-29 DOI: 10.1103/PHYSREVB.103.L121104

J. Nasu, M. Naka

{"title":"Spin Seebeck effect in nonmagnetic excitonic insulators","authors":"J. Nasu, M. Naka","doi":"10.1103/PHYSREVB.103.L121104","DOIUrl":"https://doi.org/10.1103/PHYSREVB.103.L121104","url":null,"abstract":"We propose a mechanism of the spin Seebeck effect attributed to excitonic condensation in a nonmagnetic insulator. We analyze a half-filled two-orbital Hubbard model with a crystalline field splitting in the strong coupling limit. In this model, the competition between the crystalline field and electron correlations brings about an excitonic insulating state, where the two orbitals are spontaneously hybridized. Using the generalized spin-wave theory and Boltzmann transport equation, we find that a spin current generated by a thermal gradient is observed in the excitonic insulating state without magnetic fields. The spin Seebeck effect originates from spin-split collective excitation modes although the ground state does not exhibit any magnetic orderings. This peculiar phenomenon is inherent in the excitonic insulating state, whose order parameter is time-reversal odd and yields a spin splitting for the collective excitation modes. We also find that the spin current is strongly enhanced and its direction is inverted in the vicinity of the phase transition to another magnetically ordered phase. We suggest that the present phenomenon is possibly observed in perovskite cobaltites with the GdFeO$_3$-type lattice distortion.","PeriodicalId":8511,"journal":{"name":"arXiv: Strongly Correlated Electrons","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84058019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Metal-insulator transition in transition metal dichalcogenide heterobilayer moiré superlattices 过渡金属二硫系异质层摩尔超晶格中的金属绝缘体跃迁

arXiv: Strongly Correlated Electrons Pub Date : 2020-11-27 DOI: 10.1103/PhysRevB.103.L241110

Nicol'as Morales-Dur'an, A. Macdonald, P. Potasz

引用次数: 29

Noncoplanar multiple-Q spin textures by itinerant frustration: Effects of single-ion anisotropy and bond-dependent anisotropy 流动受挫的非共面多q自旋织构:单离子各向异性和键相关各向异性的影响

arXiv: Strongly Correlated Electrons Pub Date : 2020-11-25 DOI: 10.1103/PHYSREVB.103.054422

S. Hayami, Y. Motome

{"title":"Noncoplanar multiple-\u0000Q\u0000 spin textures by itinerant frustration: Effects of single-ion anisotropy and bond-dependent anisotropy","authors":"S. Hayami, Y. Motome","doi":"10.1103/PHYSREVB.103.054422","DOIUrl":"https://doi.org/10.1103/PHYSREVB.103.054422","url":null,"abstract":"We theoretically investigate multiple-$Q$ spin textures, which are composed of superpositions of spin density waves with different wave numbers, for an effective spin model of centrosymmetric itinerant magnets. Our focus is on the interplay between biquadratic interactions arising from the spin-charge coupling and magnetic anisotropy caused by the spin-orbit coupling. Taking into account two types of the magnetic anisotropy, single-ion anisotropy and bond-dependent anisotropy, we elucidate magnetic phase diagrams for an archetypal triangular-lattice system in the absence and presence of an external magnetic field. In the case of the single-ion anisotropy, we find a plethora of multiple-$Q$ instabilities depending on the strength and the sign of the anisotropy (easy plane or easy axis), including a skyrmion crystal with topological number of two. In an external magnetic field, we find that a skyrmion crystal with topological number of one is stabilized by the in-plane (out-of-plane) magnetic field under the easy-plane (easy-axis) anisotropy. We also examine the stability of the field-induced skyrmion crystal by rotating the field direction. As a biproduct, we show that a meron crystal with the skyrmion number of one half appears in the presence of the biquadratic interaction and the easy-axis anisotropy. Meanwhile, we find that the bond-dependent anisotropy also stabilizes both types of skyrmion crystals. We show that, however, for the skyrmion crystal with topological number of one, Bloch- and Neel-type skyrmion crystals are selectively realized depending on the sign of the bond-dependent anisotropy. Moreover, we find yet another multiple-$Q$ states, including a meron crystal and a double meron crystal with the skyrmion number of one. The systematic investigation will provide a reference to complex magnetic textures in centrosymmetric magnetic metals.","PeriodicalId":8511,"journal":{"name":"arXiv: Strongly Correlated Electrons","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90427331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16

The antiferromagnetic $S=1/2$ Heisenberg model on the C$_{60}$ fullerene geometry C$_{60}$富勒烯几何上的反铁磁$S=1/2$ Heisenberg模型

arXiv: Strongly Correlated Electrons Pub Date : 2020-11-24 DOI: 10.21468/SCIPOSTPHYS.10.4.087

R. Rausch, Cassian Plorin, M. Peschke

{"title":"The antiferromagnetic $S=1/2$ Heisenberg model on the C$_{60}$ fullerene geometry","authors":"R. Rausch, Cassian Plorin, M. Peschke","doi":"10.21468/SCIPOSTPHYS.10.4.087","DOIUrl":"https://doi.org/10.21468/SCIPOSTPHYS.10.4.087","url":null,"abstract":"We solve the quantum-mechanical antiferromagnetic Heisenberg model with spins positioned on vertices of the truncated icosahedron using the density-matrix renormalization group (DMRG). This describes magnetic properties of the undoped C$_{60}$ fullerene at half filling in the limit of strong on-site interaction $U$. We calculate the ground state and correlation functions for all possible distances, the lowest singlet and triplet excited states, as well as thermodynamic properties, namely the specific heat and spin susceptibility. We find that unlike the exactly solvable C$_{20}$ to C$_{32}$, the lowest excited state is a triplet rather than a singlet, indicating a reduced frustration due to the presence of many hexagon faces and the separation of the pentagon faces. This implies that frustration may be tuneable within the fullerenes by changing their size. The spin-spin correlations are much stronger along the hexagon bonds and rapidly decrease with distance, so that the molecule is large enough not to be correlated across its whole extent. The specific heat shows a high-temperature peak and a low-temperature shoulder reminiscent of the Kagom'e lattice, while the spin susceptibility shows a single broad peak and is very close to the one of C$_{20}$.","PeriodicalId":8511,"journal":{"name":"arXiv: Strongly Correlated Electrons","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82503214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Dimensional crossover and phase transitions in coupled chains: Density matrix renormalization group results 耦合链中的维度交叉和相变:密度矩阵重整化群结果

arXiv: Strongly Correlated Electrons Pub Date : 2020-11-24 DOI: 10.1103/physrevb.102.195145

Gunnar Bollmark, N. Laflorencie, A. Kantian

{"title":"Dimensional crossover and phase transitions in coupled chains: Density matrix renormalization group results","authors":"Gunnar Bollmark, N. Laflorencie, A. Kantian","doi":"10.1103/physrevb.102.195145","DOIUrl":"https://doi.org/10.1103/physrevb.102.195145","url":null,"abstract":"Quasi-one-dimensional (Q1D) systems, i.e., three- and two-dimensional (3D/2D) arrays composed of weakly coupled one-dimensional lattices of interacting quantum particles, exhibit rich and fascinating physics. They are studied across various areas of condensed matter and ultracold atomic lattice-gas physics, and are often marked by dimensional crossover as the coupling between one-dimensional systems is increased or temperature decreased, i.e., the Q1D system goes from appearing largely 1D to largely 3D. Phase transitions occurring along the crossover can strongly enhance this effect. Understanding these crossovers and associated phase transitions can be challenging due to the very different elementary excitations of 1D systems compared to higher-dimensional ones. In the present work, we combine numerical matrix product state (MPS) methods with mean-field (MF) theory to study paradigmatic cases of dimensional crossovers and the associated phase transitions in systems of both hard-core and soft-core lattice bosons, with relevance to both condensed matter physics and ultracold atomic gases. We show that the superfluid-to-insulator transition is a first order one, as opposed to the isotropic cases and calculate transition temperatures for the superfluid states, finding excellent agreement with analytical theory. At the same time, our MPS+MF approach keeps functioning well where the current analytical framework cannot be applied. We further confirm the qualitative and quantitative reliability of our approach by comparison to exact quantum Monte Carlo calculations for the full 3D arrays.","PeriodicalId":8511,"journal":{"name":"arXiv: Strongly Correlated Electrons","volume":"103 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88954858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Phase transition into an instanton crystal state 相变到瞬时晶体状态

arXiv: Strongly Correlated Electrons Pub Date : 2020-11-24 DOI: 10.1103/PHYSREVB.103.075121

G. A. Starkov, K. Efetov

引用次数: 3

Quantum versus thermal fluctuations in the fcc antiferromagnet: Alternative routes to order by disorder fcc反铁磁体中的量子与热涨落:由无序到有序的替代途径

arXiv: Strongly Correlated Electrons Pub Date : 2020-11-23 DOI: 10.1103/PhysRevB.102.220405

R. Schick, T. Ziman, M. Zhitomirsky

引用次数: 8