Coulomb Drag between Quantum Wires

TL;DR

This paper investigates Coulomb drag in parallel quantum wires using the Luttinger liquid model, revealing divergent resistivity at zero temperature, power-law behavior at high temperatures, and exponential suppression below a crossover temperature, with effects sensitive to wire parameters.

Contribution

It provides a detailed analysis of Coulomb drag in 1D quantum wires, highlighting the strong effects of interactions and the influence of spin gaps on trans-resistivity, extending previous understanding of low-dimensional electron systems.

Findings

Trans-resistivity diverges at zero temperature due to charge density wave locking.

At high temperatures, resistivity follows a power law dependent on interaction strength.

Spin gaps cause the trans-resistivity to vanish at zero temperature.

Abstract

We study Coulomb drag in a pair of parallel one-dimensional electron systems within the framework of the Tomanaga-Luttinger model. We find that Coulomb coupling has a much stronger effect on one dimensional wires than on two-dimensional layers: At zero temperature the trans-resistivity {\em diverges}, due to the formation of locked charge density waves. At temperature well above a cross-over temperature $T^*$ the trans-resistivity follows a power law $\rho \propto T^x$, where the interaction-strength dependent exponent $x$ is determined by the Luttinger Liquid parameter $K_{c-}$ of the relative charge mode. At temperature below $T^*$ relative charge displacements are enabled by solitonic excitations, reflected by an exponential temperature dependence. The cross-over temperature $T^*$ depends sensitively on the wire width, inter-wire distance, Fermi wavelength and the effective Bohr radius. For wire distances $\bar{d} \gg k_F^{-1}$ it is exponentially suppressed with $T/E_F \sim \exp[ - \bar{d} k_F / (1-K_{c-}) ]$. The behavior changes drastically if each of the two wires develop spin gaps. In this case we find that the trans-resistivity {\em vanishes} at zero temperature. We discuss our results in view of possible experimental realizations in GaAs-AlGaAs semiconductor structures.