# Groupe de Physique Statistique

## Equipe 106, Institut Jean Lamour

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### Articles dans des revues à comité de lecture

 Relaxation in the XX quantum chain Platini T., Karevski D. J. Phys. A: Math. Theor. 40 (2007) 1711-1726 DOI : 10.1088/1751-8113/40/8/002 ArXiv : cond-mat/0611673 [PDF] We present the results obtained on the magnetisation relaxation properties of an XX quantum chain in a transverse magnetic field. We first consider an initial thermal kink-like state where half of the chain is initially thermalized at a very high temperature $T_b$ while the remaining half, called the system, is put at a lower temperature $T_s$. From this initial state, we derive analytically the Green function associated to the dynamical behaviour of the transverse magnetisation. Depending on the strength of the magnetic field and on the temperature of the system, different regimes are obtained for the magnetic relaxation. In particular, with an initial droplet-like state, that is a cold subsystem of finite size in contact at both ends with an infinite temperature environnement, we derive analytically the behaviour of the time-dependent system magnetisation.