Quantum quenches in an XXZ spin chain from a spatially inhomogeneous initial state

Jarrett Lancaster, Aditi Mitra

    Research output: Contribution to journalArticle

    Abstract

    Results are presented for the nonequilibrium dynamics of a quantum XXZ -spin chain whose spins are initially arranged in a domain wall profile via the application of a magnetic field in the z direction, which is spatially varying along the chain. The system is driven out of equilibrium in two ways: a). by rapidly turning off the magnetic field, b). by rapidly quenching the interactions at the same time as the magnetic field is turned off. The time evolution of the domain wall profile as well as various two-point spin correlation functions are studied by the exact solution of the fermionic problem for the XX chain and via a bosonization approach and a mean-field approach for the XXZ chain. At long times the magnetization is found to equilibrate (reach the ground state value), while the two-point correlation functions in general do not. In particular, for quenches within the gapless XX phase, the spin correlation function transverse to the z direction acquires a spatially inhomogeneous structure at long times whose details depend on the initial domain wall profile. The spatial inhomogeneity is also recovered for the case of classical spins initially arranged in a domain wall profile and shows that the inhomogeneities arise due to the dephasing of transverse spin components as the domain wall broadens. A generalized Gibbs ensemble approach is found to be inadequate in capturing this spatially inhomogeneous state.

    Original languageEnglish (US)
    Article number061134
    JournalPhysical Review E
    Volume81
    Issue number6
    DOIs
    StatePublished - Jun 30 2010

    Fingerprint

    Spin Chains
    Domain Wall
    domain wall
    z direction
    Correlation Function
    Magnetic Field
    Inhomogeneity
    profiles
    Transverse
    inhomogeneity
    Quantum Spin Chain
    Bosonization
    Nonequilibrium Dynamics
    magnetic fields
    Quenching
    Magnetization
    Mean Field
    Ground State
    Ensemble
    Exact Solution

    ASJC Scopus subject areas

    • Condensed Matter Physics
    • Statistical and Nonlinear Physics
    • Statistics and Probability

    Cite this

    Quantum quenches in an XXZ spin chain from a spatially inhomogeneous initial state. / Lancaster, Jarrett; Mitra, Aditi.

    In: Physical Review E, Vol. 81, No. 6, 061134, 30.06.2010.

    Research output: Contribution to journalArticle

    Lancaster, Jarrett ; Mitra, Aditi. / Quantum quenches in an XXZ spin chain from a spatially inhomogeneous initial state. In: Physical Review E. 2010 ; Vol. 81, No. 6.
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