Theory of momentum resolved tunneling into a short quantum wire

TL;DR

This paper analyzes momentum-resolved tunneling into a short quantum wire with few electrons, deriving general theorems, exact solutions for small N, and exploring the large N limit with Luttinger-liquid theory, relevant for recent experiments.

Contribution

It provides the first detailed theoretical analysis of momentum-resolved tunneling in short quantum wires, including exact calculations for small electron numbers and a large N approximation.

Findings

Derived general theorems on momentum dependence

Performed exact calculations for up to N=4 electrons

Analyzed the large N limit using Luttinger-liquid theory

Abstract

Motivated by recent tunneling experiments in the parallel wire geometry, we calculate results for momentum resolved tunneling into a short one-dimensional wire, containing a small number of electrons. We derive some general theorems about the momentum dependence, and we carry out exact calculations for up to N=4 electrons in the final state, for a system with screened Coulomb interactions that models the situation of the experiments. We also investigate the limit of large $N$ using a Luttinger-liquid type analysis. We consider the low-density regime, where the system is close to the Wigner crystal limit, and where the energy scale for spin excitations can be much lower than for charge excitations, and we consider temperatures intermediate between the relevant spin energies and charge excitations, as well as temperatures below both energy scales.