Nonperturbative interaction effects in the thermodynamics of disordered wires
Abstract
We study nonperturbative interaction corrections to the thermodynamic quantities of multichannel disordered wires in the presence of the Coulomb interactions. Within the replica nonlinear σ model (NLσM) formalism, they arise from nonperturbative soliton saddle points of the NLσM action. The problem is reduced to evaluating the partition function of a replicated classical onedimensional 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})≳lnN_{ch} , the gas is dimerized, i.e., consists of bound neutral pairs. At lower temperatures, lnN_{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})∼lnN_{ch} and may be studied independently from the perturbative effects. Specializing on the hightemperature regime, we obtain the leading nonperturbative correction to the wire heat capacity. Its ratio to the heat capacity for noninteracting electrons, C_{0} , is δC/C_{0}∼N_{ch}G^{2}(L_{T})e^{2G(LT)} .
 Publication:

Physical Review B
 Pub Date:
 December 2007
 DOI:
 10.1103/PhysRevB.76.235108
 arXiv:
 arXiv:0708.0590
 Bibcode:
 2007PhRvB..76w5108P
 Keywords:

 73.21.Hb;
 73.23.Hk;
 73.20.Fz;
 Quantum wires;
 Coulomb blockade;
 singleelectron tunneling;
 Weak or Anderson localization;
 Condensed Matter  Mesoscale and Nanoscale Physics;
 Condensed Matter  Disordered Systems and Neural Networks
 EPrint:
 18 pages