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 one-dimensional Coulomb gas. The state of the latter depends on two parameters: the number of transverse channels in the wire Nch and the dimensionless conductance G(LT) of a wire segment of length equal to the thermal diffusion length LT . At relatively high temperatures, G(LT)≳lnNch , the gas is dimerized, i.e., consists of bound neutral pairs. At lower temperatures, lnNch≳G(LT)≳1 , the pairs overlap and form a Coulomb plasma. The crossover between the two regimes occurs at a parametrically large conductance G(LT)∼lnNch 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, C0 , is δC/C0∼NchG2(LT)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;
- single-electron tunneling;
- Weak or Anderson localization;
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Disordered Systems and Neural Networks
- E-Print:
- 18 pages