Spinless Hartree-Fock model of persistent current in rings with single scatterer: Comparison with correlated models

TL;DR

This paper demonstrates that a spinless Hartree-Fock model can accurately predict persistent current behavior in a one-dimensional ring with a scatterer, aligning well with correlated models like Luttinger liquids.

Contribution

It shows that the Hartree-Fock approximation captures key features of persistent currents typically associated with correlated many-body models.

Findings

Persistent current decays faster than L^{-1} with ring size.

Current exhibits a sine dependence on magnetic flux.

Power-law decay matches predictions from correlated models.

Abstract

Using the self-consistent Hartree-Fock approximation for spinless electrons at zero temperature, we study the persistent current of the interacting electron gas in a one-dimensional continuous ring containing a single $\delta$ barrier. We calculate the persistent current as a function of the ring circumference, magnetic flux threading the ring, barrier strength, etc. We compare our results with the results of correlated models like the Luttinger liquid model and the Hubbard model solved by means of the renormalization group. A good agreement is found. First, the persistent current decays with the increasing ring circumference ($L$) faster than $L^{-1}$ and eventually like $L^{-\alpha-1}$, where $\alpha>0$ depends only on the electron-electron interaction. Second, the persistent current is a sine-shaped function of magnetic flux. This sine-like dependence and in particular the universal power law $L^{-\alpha-1}$ have sofar been believed to arise only in the correlated many-body models. Observation of these features within the Hartree-Fock model is a surprising result.