Quantum quench dynamics in XY spin chain with ferromagnetic and antiferromagnetic interactions

Prethermalization in a nonintegrable quantum spin chain after a quench.

We study the dynamics of a quantum Ising chain after the sudden introduction of a nonintegrable long-range interaction. Via an exact mapping onto a fully connected lattice of hard-core bosons, we show that a prethermal state emerges and we investigate its features by focusing on a class of physically relevant observables. In order to gain insight into the eventual thermalization, we outline a d...

Relaxation of antiferromagnetic order in spin-1/2 chains following a quantum quench.

We study the unitary time evolution of antiferromagnetic order in anisotropic Heisenberg chains that are initially prepared in a pure quantum state far from equilibrium. Our analysis indicates that the antiferromagnetic order imprinted in the initial state vanishes exponentially. Depending on the anisotropy parameter, oscillatory or nonoscillatory relaxation dynamics is observed. Furthermore, t...

Competition of Ferromagnetic and Antiferromagnetic Order in the Spin-1/2 Xxz Chain at Finite Temperature

An analytical study is presented of the crossover in the gapless attractive XXZ chain from antiferromagnetic to ferromagnetic behaviour at low to high temperature, respectively. In particular, an analytic formula for the crossover in the long distance asymptotics and explicit results for the nearest-neighbour longitudinal correlation are obtained. We also provide results for the specific heat a...

The Quasi-crystalline Quantum Spin-1⁄2 Xy-chain

Dynamics of the antiferromagnetic Heisenberg spin − 1 / 2 chain

In magnetic systems, interactions between electrons can be described by an effective spinspin interaction. When the wavefunctions of the electrons overlap mainly in one direction, the system behaves as an effectively one-dimensional spin chain. A special class of such a spin chain is the anisotropic Heisenberg model, also called the XXZ model. Exact wavefunctions for the (gapped) antiferromagne...