Unification of electromagnetic noise and Luttinger liquid via a quantum dot

TL;DR

This paper explores how dissipation affects a quantum dot coupled to a chiral Luttinger liquid, revealing a mapping to the Caldeira-Leggett model and analyzing the special case near $K=1/2^+$.

Contribution

It introduces a mapping of the dissipative quantum dot problem to the Caldeira-Leggett model, incorporating the effects of Coulomb interactions and dissipation in Luttinger liquids.

Findings

Dissipation can be modeled as an ohmic bath with effective strength $ ilde{K}$.

The case $K=1/2^+$ is analyzed using the spin-boson-fermion model.

Experimental implications of dissipation effects are discussed.

Abstract

We investigate the effect of dissipation on a small quantum dot (resonant level) tunnel-coupled to a chiral Luttinger liquid (LL) with the LL parameter $K$. The dissipation stems from the coupling of the dot to an electric environment, being characterized by the resistance $R$, via Coulomb interactions. We show that this problem can be mapped onto a Caldeira-Leggett model where the (ohmic) bath of harmonic oscillators is governed by the effective dissipation strength $\alpha=(2\tilde{K})^{-1}$ with $\tilde{K}^{-1}=K^{-1}+2R/R_K$ and $R_K=h/e^2$ the quantum of resistance. Experimental consequences are discussed and the limit $K=1/2^+$ is thoroughly studied at small $R/R_K$ through the spin-boson-fermion model.