Probing the role of long-range interactions in the dynamics of a long-range Kitaev chain

Article

关键词: MANY-BODY LOCALIZATION;    COSMOLOGICAL EXPERIMENTS;    PHASE-TRANSITION;    QUANTUM;    THERMALIZATION;    RELAXATION;    SYSTEMS;    MODELS;   

DOI  :  10.1103/PhysRevB.96.125113

来源: SCIE

【 摘 要 】

We study the role of long-range interactions (more precisely, the long-range superconducting gap term) on the nonequilibrium dynamics considering a long-range p-wave superconducting chain in which the superconducting term decays with distance between two sites in a power-law fashion characterized by an exponent a. We show that the Kibble-Zurek scaling exponent, dictating the power-law decay of the defect density in the final state reached following a slow (in comparison to the time scale associated with the minimum gap in the spectrum of the Hamiltonian) quenching of the chemical potential mu across a quantum critical point, depends nontrivially on the exponent alpha as long as alpha < 2; on the other hand, for alpha > 2, we find that the exponent saturates to the corresponding well-known value of 1/2 expected for the short-range model. Furthermore, studying the dynamical quantum phase transitions manifested in the nonanalyticities in the rate function of the return possibility I (t) in subsequent temporal evolution following a sudden change in mu, we show the existence of a new region; in this region, we find three instants of cusp singularities in I (t) associated with a single sector of Fisher zeros. Notably, the width of this region shrinks as a increases and vanishes in the limit alpha -> 2, indicating that this special region is an artifact of the long-range nature of the Hamiltonian.

【 授权许可】

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