Interplay between phase defects and spin polarization in the specific heat of the spin density wave compound (TMTTF)_2Br in a magnetic field

TL;DR

This study investigates how magnetic fields influence the ground state and spin configurations in the SDW compound (TMTTF)$_2$Br, revealing a magnetic field-induced density wave glass through heat relaxation experiments.

Contribution

It introduces a local strong pinning model explaining the deconfinement of soliton-antisoliton pairs and the formation of a density wave glass under magnetic fields in (TMTTF)$_2$Br.

Findings

Magnetic fields alter the ground state of (TMTTF)$_2$Br.

Deconfinement of soliton-antisoliton pairs occurs due to Zeeman coupling.

A magnetic field induces a density wave glass state.

Abstract

Equilibrium heat relaxation experiments provide evidence that the ground state of the commensurate spin density wave (SDW) compound (TMTTF)$_2$Br after the application of a sufficient magnetic field is different from the conventional ground state. The experiments are interpreted on the basis of the local model of strong pinning as the deconfinement of soliton-antisoliton pairs triggered by the Zeeman coupling to spin degrees of freedom, resulting in a magnetic field induced density wave glass for the spin carrying phase configuration.