Dimensional crossover and deconfinement in Bechgaard salts

TL;DR

This paper investigates the dimensional crossover and deconfinement transition in Bechgaard salts, using a chain-DMFT approach to model the transition from a one-dimensional Mott insulator to a higher-dimensional metal, and analyzes its physical consequences.

Contribution

The study introduces a dynamical mean field method (chain-DMFT) to accurately reproduce and analyze the deconfinement transition in coupled Hubbard chains, providing insights into physical properties.

Findings

Reproduces the deconfinement transition using chain-DMFT.

Determines transport properties transverse to chains.

Analyzes Fermi surface shape and quasiparticle residues.

Abstract

The Bechgaard salts are made of weakly coupled one dimensional chains. This particular structure gives the possibility to observe in these systems a dimensional crossover between a high temperature (or high energy) one dimensional phase and a two or three dimensional system. Since the filling of the chains is commensurate the system thus undergoes a deconfinement transition from a one dimensional Mott insulator to a two (or three) dimensional metal. Such a transition has of course a strong impact on the physical properties of these compounds, and is directly seen in transport measurements. In order to describe such a transition a dynamical mean field method has been introduced (chain-DMFT). Using this method we investigate a system of coupled Hubbard chains and show that we can indeed reproduce the deconfinement transition. This allows to determine physical quantities such as the transport transverse to the chains and the shape of the Fermi surface and quasiparticle residues in the low temperature phase.