Diverging conductance at the contact between random and pure quantum XX spin chains

Christophe Chatelain (1)

1 IJL - Institut Jean Lamour

A model consisting in two quantum XX spin chains, one homogeneous and the second with random couplings drawn from a binary distribution, is considered. The two chains are coupled to two different non-local thermal baths and their dynamics is governed by a Lindblad equation. In the steady state, a current J is induced between the two chains by coupling them together by their edges and imposing different chemical potentials µ to the two baths. While a regime of linear characteristics J versus ∆µ is observed in the absence of randomness, a gap opens as the disorder strength is increased. In the infinite-randomness limit, this behavior is related to the density of states of the localized states contributing to the current. The conductance is shown to diverge in this limit.

Mots clés: Quantum spin chains; Transport; Disorder

Domaines: Mécanique statistique [cond-mat.stat-mech]

Christophe Chatelain. Diverging conductance at the contact between random and pure quantum XX spin chains. Journal of Statistical Mechanics: Theory and Experiment, 2017, pp.113301. ⟨10.1088/1742-5468/aa933f⟩. ⟨hal-01559725v2⟩