Quantum transport of topological spin solitonsin a one-dimensional organic ferroelectric

TL;DR

This study investigates the quantum transport of topological spin solitons in a one-dimensional organic ferroelectric, revealing highly mobile solitons driven by quantum fluctuations near a critical point.

Contribution

It demonstrates the existence and mobility of spin solitons in a ferroelectric spin-Peierls state, highlighting quantum fluctuations' role in enabling topological transport.

Findings

Spin solitons are emergent topological defects in the FSP state.

Solitons exhibit high mobility even at low temperatures.

Quantum fluctuations near a critical point facilitate soliton motion.

Abstract

We report the dielectric, magnetic, and ultrasonic properties of a one-dimensional organic salt TTF-QBr$_3$I. These indicate that TTF-QBr$_3$I shows a ferroelectric spin-Peierls (FSP) state in a quantum critical regime. In the FSP state, coupling of charge, spin, and lattice leads to emergent excitation of spin solitons as topological defects. Amazingly, the solitons are highly mobile even at low temperatures, although they are normally stationary because of pinning. Our results suggest that strong quantum fluctuations enhanced near a quantum critical point enable soliton motion governed by athermal relaxation. This indicates the realization of quantum topological transport at ambient pressure.