Nonperturbative interaction effects in the thermodynamics of disordered wires

[摘要] We study nonperturbative interaction corrections to the thermodynamic quantities of multichannel disordered wires in the presence of the Coulomb interactions. Within the replica nonlinear sigma-model (NL sigma M) formalism, they arise from nonperturbative soliton saddle points of the NL sigma M action. The problem is reduced to evaluating the partition function of a replicated classical one-dimensional Coulomb gas. The state of the latter depends on two parameters: the number of transverse channels in the wire N-ch and the dimensionless conductance G(L-T) of a wire segment of length equal to the thermal diffusion length L-T. At relatively high temperatures, G(L-T)>= ln N-ch, the gas is dimerized, i.e., consists of bound neutral pairs. At lower temperatures, ln N-ch >= G(L-T)>= 1, the pairs overlap and form a Coulomb plasma. The crossover between the two regimes occurs at a parametrically large conductance G(L-T)similar to ln N-ch and may be studied independently from the perturbative effects. Specializing on the high-temperature regime, we obtain the leading nonperturbative correction to the wire heat capacity. Its ratio to the heat capacity for noninteracting electrons, C-0, is delta C/C-0 similar to N(ch)G(2)(L-T)e(T)(-2G(L)).

[发布日期] 2007-12-01

[关键词] COULOMB-BLOCKADE