arXiv: Strongly Correlated Electrons最新文献_第6页

Flux crystals, Majorana metals, and flat bands in exactly solvable spin-orbital liquids 通量晶体，马约拉纳金属，以及精确可溶自旋轨道液体中的平带

arXiv: Strongly Correlated Electrons Pub Date : 2020-10-27 DOI: 10.1103/PHYSREVB.103.075144

Sreejith Chulliparambil, L. Janssen, M. Vojta, Hong-Hao Tu, Urban F. P. Seifert

{"title":"Flux crystals, Majorana metals, and flat bands in exactly solvable spin-orbital liquids","authors":"Sreejith Chulliparambil, L. Janssen, M. Vojta, Hong-Hao Tu, Urban F. P. Seifert","doi":"10.1103/PHYSREVB.103.075144","DOIUrl":"https://doi.org/10.1103/PHYSREVB.103.075144","url":null,"abstract":"Spin-orbital liquids are quantum disordered states in systems with entangled spin and orbital degrees of freedom. We study exactly solvable spin-orbital models in two dimensions with selected Heisenberg-, Kitaev-, and $Gamma$-type interactions, as well as external magnetic fields. These models realize a variety of spin-orbital-liquid phases featuring dispersing Majorana fermions with Fermi surfaces, nodal Dirac or quadratic band touching points, or full gaps. In particular, we show that Zeeman magnetic fields can stabilize nontrivial flux patterns and induce metamagnetic transitions between states with different topological character. Solvable nearest-neighbor biquadratic spin-orbital perturbations can be tuned to stabilize zero-energy flat bands. We discuss in detail the examples of $mathrm{SO}(2)$- and $mathrm{SO}(3)$-symmetric spin-orbital models on the square and honeycomb lattices, and use group-theoretical arguments to generalize to $mathrm{SO}(nu)$-symmetric models with arbitrary integer $nu > 1$. These results extend the list of exactly solvable models with spin-orbital-liquid ground states and highlight the intriguing general features of such exotic phases. Our models are thus excellent starting points for more realistic modellings of candidate materials.","PeriodicalId":8511,"journal":{"name":"arXiv: Strongly Correlated Electrons","volume":"67 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73784279","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: 10

Investigation of the effective interactions for the Emery model by the constrained random-phase approximation and constrained functional renormalization group 用约束随机相位近似和约束泛函重整化群研究Emery模型的有效相互作用

arXiv: Strongly Correlated Electrons Pub Date : 2020-10-27 DOI: 10.1103/PHYSREVB.103.125130

Xing-Jie Han, P. Werner, C. Honerkamp

{"title":"Investigation of the effective interactions for the Emery model by the constrained random-phase approximation and constrained functional renormalization group","authors":"Xing-Jie Han, P. Werner, C. Honerkamp","doi":"10.1103/PHYSREVB.103.125130","DOIUrl":"https://doi.org/10.1103/PHYSREVB.103.125130","url":null,"abstract":"The effective interaction of downfolded low-energy models for electrons in solids can be obtained by integrating out the high energy bands away from the target band near the Fermi level. Here, we apply the constrained random-phase approximation (cRPA) and constrained functional renormalization group (cfRG), which can go beyond cRPA by including all one-loop diagrams, to calculate and compare the effective interactions of the three-band Emery model, which is often used to investigate cuprate high-temperature superconductors. At half band filling, we find that the effective interaction increases as the charge transfer energy ($Delta_{dp}$) increases and similar behavior is obtained as a function of the interatomic 2$p$-3$d$ interaction ($U_{dp}$). However, the effective interaction is more sensitive to $Delta_{dp}$ than $ U_{dp}$. For most of the parameter sets, the effective static interaction is overscreened in cRPA compared to cfRG. The low-energy models at half-filling are solved within dynamical mean-field theory (DMFT). The results show that despite the different static interactions, the systems with cRPA and cfRG interaction exhibit a Mott transition at similar values of $Delta_{dp}$. We also investigate the effective interaction as a function of doping. The cfRG effective interaction decreases as the electron number increases and displays a trend opposite to that of cRPA. Antiscreening is observed for the hole-doped case. For all the cases studied, the near-cancellation of the direct particle-hole channel is observed. This indicates that at least for the downfolding of the onsite interaction terms, methods beyond cRPA may be required.","PeriodicalId":8511,"journal":{"name":"arXiv: Strongly Correlated Electrons","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86349347","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

Pressure-induced phase transition in the J1−J2 square lattice antiferromagnet RbMoOPO4Cl J1−J2方晶格反铁磁体RbMoOPO4Cl的压力诱导相变

arXiv: Strongly Correlated Electrons Pub Date : 2020-10-26 DOI: 10.1103/PHYSREVB.103.104406

H. Takeda, T. Yamauchi, M. Takigawa, H. Ishikawa, Z. Hiroi

{"title":"Pressure-induced phase transition in the \u0000J1−J2\u0000 square lattice antiferromagnet \u0000RbMoOPO4Cl","authors":"H. Takeda, T. Yamauchi, M. Takigawa, H. Ishikawa, Z. Hiroi","doi":"10.1103/PHYSREVB.103.104406","DOIUrl":"https://doi.org/10.1103/PHYSREVB.103.104406","url":null,"abstract":"We report results of magnetization and $^{31}$P NMR measurements under high pressure up to 6.4~GPa on RbMoOPO$_4$Cl, which is a frustrated square-lattice antiferromagnet with competing nearest-neighbor and next-nearest-neighbor interactions. Anomalies in the pressure dependences of the NMR shift and the transferred hyperfine coupling constants indicate a structural phase transition at 2.6~GPa, which is likely to break mirror symmetry and triggers significant change of the exchange interactions. In fact, the NMR spectra in magnetically ordered states reveal a change from the columnar antiferromagnetic (CAF) order below 3.3~GPa to the Neel antiferromagnetic (NAF) order above 3.9~GPa. The spin lattice relaxation rate $1/T_1$ also indicates a change of dominant magnetic fluctuations from CAF-type to NAF-type with pressure. Although the NMR spectra in the intermediate pressure region between 3.3 and 3.9 GPa show coexistence of the CAF and NAF phases, a certain component of $1/T_1$ shows paramagnetic behavior with persistent spin fluctuations, leaving possibility for a quantum disordered phase. The easy-plane anisotropy of spin fluctuations with unusual nonmonotonic temperature dependence at ambient pressure gets reversed to the Ising anisotropy at high pressures. This unexpected anisotropic behavior for a spin 1/2 system may be ascribed to the strong spin-orbit coupling of Mo-4$d$ electrons.","PeriodicalId":8511,"journal":{"name":"arXiv: Strongly Correlated Electrons","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73448197","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: 2

Cluster glass transition and relaxation in the random spinel CoGa2O4 随机尖晶石CoGa2O4中的团簇玻璃化转变和弛豫

arXiv: Strongly Correlated Electrons Pub Date : 2020-10-26 DOI: 10.1103/PhysRevB.103.224408

T. Naka, T. Nakane, S. Ishii, M. Nakayama, A. Ohmura, F. Ishikawa, A. de Visser, H. Abe, T. Uchikoshi

{"title":"Cluster glass transition and relaxation in the random spinel \u0000CoGa2O4","authors":"T. Naka, T. Nakane, S. Ishii, M. Nakayama, A. Ohmura, F. Ishikawa, A. de Visser, H. Abe, T. Uchikoshi","doi":"10.1103/PhysRevB.103.224408","DOIUrl":"https://doi.org/10.1103/PhysRevB.103.224408","url":null,"abstract":"We report magnetic properties in the random spinel magnet CoGa2O4. Rietveld analysis of the x-ray diffraction profile for CoGa2O4 reveals that the Co and Ga ions are distributed randomly in the tetrahedral A-sites and octahedral B-sites in the cubic spinel structure. CoGa2O4 exhibits a spin-glass transition at TSG = 8.2 K that is confirmed by measurements of the dc- and ac-susceptibilities and thermoremanent magnetization (TRM) that develops below TSG. From the frequency dependence of the freezing temperature Tf for CoGa2O4, it is indicated that the relaxation time follows a Vogel-Fulcher law. Magnetic entropy is considerably reduced, probably because magnetic cluster formation developed even at T > TSG. The relaxation rate of TRM is considerably enhanced at TSG and decays rapidly above and below TSG. The time course of TRM is reproduced by non-exponential relaxation forms, such as a stretched exponential (Kohlrausch) as well as Ogielski and Weron relaxation forms. This behavior is displayed universally in glass systems, and the characteristic parameters associated with these functions were reasonable.","PeriodicalId":8511,"journal":{"name":"arXiv: Strongly Correlated Electrons","volume":"66 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82174804","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: 3

Trimeron-phonon coupling in magnetite 磁铁矿中的三介子-声子耦合

arXiv: Strongly Correlated Electrons Pub Date : 2020-10-22 DOI: 10.1103/PHYSREVB.103.104303

P. Piekarz, D. Legut, E. Baldini, Carina A. Belvin, T. Kolodziej, W. Tabiś, A. Kozłowski, Z. Kąkol, Z. Tarnawski, J. Lorenzana, N. Gedik, A. Oleś, J. Honig, K. Parlinski

引用次数: 6

Magnetoelectric generation of a Majorana-Fermi surface in Kitaev's honeycomb model 基塔耶夫蜂巢模型中马约拉纳-费米曲面的磁电产生

arXiv: Strongly Correlated Electrons Pub Date : 2020-10-21 DOI: 10.1103/PhysRevB.103.134444

R. Chari, R. Moessner, J. Rau

引用次数: 1

Strong tuning of magnetism and electronic structure by spin orientation 通过自旋取向对磁性和电子结构进行强调谐

arXiv: Strongly Correlated Electrons Pub Date : 2020-10-21 DOI: 10.1103/PhysRevB.102.180401

Y. Weng, Xing’ao Li, S. Dong

引用次数: 2

Geometrical Hall effect and momentum-space Berry curvature from spin-reversed band pairs 自旋反转带对的几何霍尔效应和动量空间Berry曲率

arXiv: Strongly Correlated Electrons Pub Date : 2020-10-19 DOI: 10.1103/PHYSREVB.103.L041111

M. Hirschberger, Y. Nomura, H. Mitamura, A. Miyake, T. Koretsune, Y. Kaneko, L. Spitz, Y. Taguchi, A. Matsuo, K. Kindo, R. Arita, M. Tokunaga, Y. Tokura

引用次数: 7

Quantum oscillations in the activated conductivity in excitonic insulators: Possible application to monolayer WTe2 激子绝缘体中活化电导率的量子振荡:可能应用于单层WTe2

arXiv: Strongly Correlated Electrons Pub Date : 2020-10-19 DOI: 10.1103/physrevb.103.l041101

P. Lee

引用次数: 16

Diagrammatic study of optical excitations in correlated systems 相关系统中光激发的图解研究

arXiv: Strongly Correlated Electrons Pub Date : 2020-10-18 DOI: 10.1103/PHYSREVB.103.104415

O. Simard, S. Takayoshi, P. Werner

引用次数: 7