Vestiges of Topological Phase Transitions in Kitaev Quantum Spin Liquids

Abstract

We investigate signatures of topological quantum phase transitions (TQPTs) between the $Z_2$ quantum spin liquids (QSLs). In two spatial dimensions, $Z_2$ QSLs and their TQPTs are only well defined at zero temperature ($T=0$), and it is imperative to clarify their observable signatures under nonzero temperatures. Here, we present the vestiges of TQPTs between $Z_2$ QSLs with Majorana fermions in terms of thermal Hall conductivity ${\kappa }_{xy}$ at nonzero temperatures. The ${\kappa }_{xy}/T$ shows characteristic temperature dependences around TQPTs. We argue that an exponential upturn near $T=0$ and the peak of ${\kappa }_{xy}/T$ around massive excitation energy are observable smoking-gun signals of the TQPTs. Quantum critical fan-shape temperature dependences are uncovered across TQPTs. We also perform the parton mean-field analysis on a modified Kitaev model with next-nearest neighbor interactions finding TQPTs between the phases with different Chern numbers and their vestiges self-consistently. We discuss the implication of our results to the recent experiments in $\alpha$-RuCl${}_3$.

arXiv comment6+3 pages (main text+supplemental material), Phys. Rev. Lett., in press

References in corpus (31)

• Berry Phase Effects on Electronic Properties
• Anyons in an exactly solved model and beyond
• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Quantum Spin Liquids
• Quantum Spin Liquid States
• Majorana quantization and half-integer thermal quantum Hall effect in a Kitaev spin liquid
• Proximate Kitaev Quantum Spin Liquid Behaviour in α-RuCl${}_3$
• Z_2 Gauge Theory of Electron Fractionalization in Strongly Correlated Systems
• Scattering Continuum and Possible Fractionalized Excitations in $\alpha$-RuCl${}_3$
• Evidence for a Field-induced Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• Dynamics of a two-dimensional quantum spin liquid: signatures of emergent Majorana fermions and fluxes
• Kitaev magnetism in honeycomb RuCl3 with intermediate spin-orbit coupling
• Fermionic response from fractionalization in an insulating two-dimensional magnet
• Unusual thermal Hall effect in a Kitaev spin liquid candidate $\alpha$-RuCl${}_3$
• Vaporization of Kitaev spin liquids
• Anomalous thermal conductivity and magnetic torque response in the honeycomb magnet $\alpha$-RuCl${}_3$
• Field-induced quantum criticality in the Kitaev system $\alpha$-RuCl${}_3$
• Emergence of a Field-Driven U(1) Spin Liquid in the Kitaev Honeycomb Model
• Doping a spin-orbit Mott Insulator: Topological Superconductivity from the Kitaev-Heisenberg Model and possible application to (Na2/Li2)IrO3
• Observation of two types of anyons in the Kitaev honeycomb magnet
• Thermal Transport in the Kitaev Model
• Quantization of the thermal Hall conductivity at small Hall angles
• Approximately quantized thermal Hall effect of chiral liquids coupled to phonons
• Quantum Thermal Hall Effect in a Time-Reversal-Symmetry-Broken Topological Superconductor in Two Dimensions : Approach From Bulk Calculations
• Phase Diagram and Quantum Order by Disorder in the Kitaev $K_1$-$K_2$ Honeycomb Magnet
• Spin Wave Analysis of Low-Temperature Thermal Hall Effect in the Candidate Kitaev Spin Liquid $\alpha$-RuCl${}_3$
• Successive Majorana Topological Transitions Driven by a Magnetic Field in the Kitaev Model
• Topological liquid nucleation induced by vortex-vortex interactions in Kitaev's honeycomb model
• Path to stable quantum spin liquids in spin-orbit coupled correlated materials
• Quasiparticle Hall Transport of d-wave Superconductors in Vortex State
• Dynamics of a quantum spin liquid beyond integrability $-$ the Kitaev-Heisenberg-$\Gamma$ model in an augmented parton mean-field theory

Cited by in corpus (14)

• Half-integer quantized anomalous thermal Hall effect in the Kitaev material $\alpha$-RuCl${}_3$
• Dynamics of visons and thermal Hall effect in perturbed Kitaev models
• Identification of a Kitaev Quantum Spin Liquid by Magnetic Field Angle Dependence
• Kitaev Quantum Spin Liquids
• Thermodynamics of 3D Kitaev quantum spin liquids via tensor networks
• Spontaneous Chiral-Spin Ordering in Spin-Orbit Coupled Honeycomb Magnets
• Thermodynamic evidence for field-angle dependent Majorana gap in a Kitaev spin liquid
• Spontaneous dimerization, spin-nematic order, and deconfined quantum critical point in a spin-1 Kitaev chain with tunable single-ion anisotropy
• Dynamics of fractionalized mean-field theories: consequences for Kitaev materials
• Majorana Fermion Mean-Field Theories of Kitaev Quantum Spin Liquids
• Nature of Topological Phase Transition of Kitaev Quantum Spin Liquids
• Phase diagram and thermal Hall conductivity of spin-liquid Kekulé-Kitaev model
• Electric polarization near vortices in the extended Kitaev model
• Topological Majorana flat bands in the Kitaev model on a Bishamon-kikko lattice