Directed transport in equilibrium

TL;DR

This paper demonstrates that a symmetry-broken dimer in thermal equilibrium can exhibit steady directed transport without external forces, gaining energy from the heat bath, challenging traditional notions of equilibrium behavior.

Contribution

It provides an exact analytical and numerical demonstration of directed transport in an equilibrium system due to symmetry breaking, offering new physical insights.

Findings

Dimer exhibits steady directed motion at hard core collision limit.

Transport occurs without external driving, driven solely by thermal energy.

Results align with thermodynamic principles, challenging conventional views.

Abstract

We investigate a symmetry broken dimer constrained to move in a particular direction when in contact with a heat-bath at a constant temperature. The dimer is not driven by any external force. The system gains kinetic energy from the heat-bath. The symmetry broken system can use this energy in directed transport. At the hard core collision limit between the particles of the dimer, we show by exact analytic calculations and complementary numerical results that the dimer undergoes steady directed transport. Our observation, being consistent with the {\it second law of thermodynamics}, {\it detailed balance} etc leads to new physical understanding to which much attention has not been paid.