Related papers: Anomalous low-frequency conductivity in easy-plane…
We investigate spin transport by thermally excited spin waves in an antiferromagnetic insulator. Starting from a stochastic Landau-Lifshitz-Gilbert phenomenology, we obtain the out-of-equilibrium spin-wave properties. In linear response to…
Using the adaptive time-dependent density matrix renormalization group method, we numerically study the spin dynamics and transport in one-dimensional spin-1/2 systems at zero temperature. Instead of computing transport coefficients from…
Quasiperiodic systems host exotic transport regimes that are distinct from those found in periodic or disordered lattices. In this work, we study quantum transport in the Aubry-Andr\'e-Harper lattice in a two-terminal setup coupled to…
We study helical structures in spin-spiral single crystals. In the continuum approach for the helicity potential energy the simple electronic band splits into two non-parabolic bands. For the Fermi energy greater than the splitting between…
The Fermi-liquid theory of superconductivity is applicable to a broad range of systems that are candidates for unconventional pairing. Fundamental differences between unconventional and conventional anisotropic superconductors are…
We study finite-temperature transport properties of the one-dimensional Hubbard model using the density matrix renormalization group. Our aim is two-fold: First, we compute both the charge and the spin current correlation function of the…
We study the thermal transport properties of several quantum spin chains and ladders. We find indications for a diverging thermal conductivity at finite temperatures for the models examined. The temperature at which the non-diverging…
We report an optical spectroscopy study of the charge-dynamics anisotropy in the La3Ni2O7 single crystals with the electric field of the incident light parallel to the crystalline c-axis and ab-plane respectively. The evolution of the…
Numerical calculations of anisotropic hopping transport based on the resistor network model are presented. Conductivity is shown to follow the stretched exponential dependence on temperature with exponents changing from 1/4 to 1 as the wave…
We explore the physics of the disordered XYZ spin chain using two complementary numerical techniques: exact diagonalization (ED) on chains of up to 17 spins, and time-evolving block decimation (TEBD) on chains of up to 400 spins. Our…
Anomalous transport processes in which the variance of the distance travelled does not necessarily increase linearly with time are modelled using the formalism of continuous time random walks. We compute particle propagators which have the…
The anisotropy of low energy (0$\sim$5eV) optical excitations in strongly correlated transition-metal oxides is closely related to the spin and orbital orderings. The recent successes of LDA+$U$ method in describing the magnetic and…
Using numerical diagonalization techniques, we explore the effect of local and bond disorder on the finite temperature spin and thermal conductivities of the one dimensional anisotropic spin-1/2 Heisenberg model. High-temperature results…
We studied the spin-dependent quantum transport properties using a simple modelling of a Datta-Das spin transistor. We refine previous results by accounting the propagation medium changes of opacity felt by itinerant electrons, when the…
We analyze and compare the effect of spatial and spin anisotropy on spin conductivity in a two dimensional S=1/2 Heisenberg quantum magnet on a square lattice. We explore the model in both the Neel antiferromagnetic (AF) phase and the…
We study the spin and heat conductivity of dimerized spin-1/2 chains in homogeneous magnetic fields at finite temperatures. At zero temperature, the model undergoes two field-induced quantum phase transitions from a dimerized, into a…
Negative differential conductivity is reported for the far from equilibrium quantum spin transport in the insulating regime (J_x < J_z) of finite Heisenberg XXZ spin 1/2 chains. The phenomenon is reproduced analytically for small chains of…
Isotropic integrable spin chains such as the Heisenberg model feature superdiffusive spin transport belonging to an as-yet-unidentified dynamical universality class closely related to that of Kardar, Parisi, and Zhang (KPZ). To determine…
The quantum spin $1/2$ XXZ chain with anisotropy parameter $\Delta=-1/2$ possesses a dynamic supersymmetry on the lattice. This supersymmetry and a generalisation to higher spin are investigated in the case of open spin chains. A family of…
We present a new framework for computing low frequency transport properties of strongly correlated, ergodic systems. Our main assumption is that, when a thermalizing diffusive system is driven at frequency $\omega$, domains of size $\xi…