Time Evolution of the Neel State

TL;DR

This paper analyzes the time evolution of the Neel state in a quasi-one-dimensional spin-1/2 chain, developing an exact superposition representation and examining its eigenstate properties across various Hamiltonians.

Contribution

It introduces an exact superposition equation for the Neel state and explores its eigenstate nature in different Hamiltonian models.

Findings

Neel state can be expressed as a superposition of maximum sublattice spin states.

The paper derives an exact equation for superposition coefficients.

Time evolution of the Neel state is studied using Fock-Krylov method.

Abstract

A quasionedimentional spin chain (s=1/2) is considered as a lattice consisting of two sublattices. The attention is paid to the states which are pure spin states of the whole lattice and both sublattices, the value of the sublattices' spins being maximum. It is shown that the Neel state can be considered as a superposition of such states. The exact equation for this superposition coefficients is developed. The possibility of the Neel state to be the eigenstate of a Hamiltonian is discussed. Several model Hamiltonians are examined, the well known ones and few novel Hamiltonians being considered. The time evolution of the Neel state in different models is studied with the help of Fock-Krylov method.