Luttinger-liquid-like transport in long InSb nanowires

TL;DR

This study investigates the electrical transport properties of long InSb nanowires, revealing Luttinger-liquid-like behavior characterized by power-law temperature dependence and nonlinear I-V characteristics, inconsistent with single-electron theories.

Contribution

It demonstrates Luttinger-liquid-like transport in long InSb nanowires, providing experimental evidence of impurity effects and weak-link density estimation.

Findings

Electrical conductance follows a power law with temperature ($G \,\propto\, T^\alpha$) with $\,\alpha \approx 4$

Current-voltage characteristics exhibit power-law behavior at low temperatures ($I \propto V^\beta$)

Transport behavior cannot be explained by single-electron theories, indicating Luttinger-liquid-like properties

Abstract

Long nanowires of degenerate semiconductor InSb in asbestos matrix (wire diameter is around 50 \AA, length 0.1 - 1 mm) were prepared. Electrical conduction of these nanowires is studied over a temperature range 1.5 - 350 K. It is found that a zero-field electrical conduction is a power function of the temperature $G\propto T^\alpha$ with the typical exponent $\alpha \approx 4$. Current-voltage characteristics of such nanowires are found to be nonlinear and at sufficiently low temperatures follows the power law $I\propto V^\beta$. It is shown that the electrical conduction of these nanowires cannot be accounted for in terms of ordinary single-electron theories and exhibits features expected for impure Luttinger liquid. For a simple approximation of impure LL as a pure one broken into drops by weak links, the estimated weak-link density is around $10^3-10^4$ per cm.