Critical quench dynamics of random quantum spin chains

Ultra-slow relaxation from initial order and delayed ordering from initial disorder

Gergö Roósz, Yu Cheng Lin, F. Iglói

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

By means of free fermionic techniques combined with multiple precision arithmetic we study the time evolution of the averagemagnetization, m(t), of the randomtransverse-field Ising chain after global quenches.Weobserve different relaxation behaviors for quenches starting from different initial states to the critical point. Starting from a fully ordered initial state, the relaxation is logarithmically slow described by, m(t) ∼ lna t , and in a finite sample of length L the averagemagnetization saturates at a size-dependent plateau mp (L)∼ L-b here the two exponents satisfy the relation b/a = ψ = 1 2. Starting from a fully disordered initial state, the magnetization stays at zero for a period of time until t = td with ln td ∼L ψ and then starts to increase until it saturates to an asymptotic value mp (L)∼ L-b'with b'≈1.5. For both quenching protocols, finite-size scaling is satisfied in terms of the scaled variable ln t Lψ. Furthermore, the distribution of long-time limiting values of the magnetization shows that the typical and the average values scale differently and the average is governed by rare events. The non-equilibrium dynamical behavior of the magnetization is explained through semi-classical theory.

Original languageEnglish
Article number023055
JournalNew Journal of Physics
Volume19
Issue number2
DOIs
Publication statusPublished - Feb 1 2017

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disorders
magnetization
guy wires
plateaus
critical point
quenching
exponents
scaling

Keywords

  • disorder effects
  • quantum ising chains
  • quantum quench dynamics

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Critical quench dynamics of random quantum spin chains : Ultra-slow relaxation from initial order and delayed ordering from initial disorder. / Roósz, Gergö; Lin, Yu Cheng; Iglói, F.

In: New Journal of Physics, Vol. 19, No. 2, 023055, 01.02.2017.

Research output: Contribution to journalArticle

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