Landauer's principle at zero temperature

TL;DR

This paper derives a new, tighter Landauer bound that remains meaningful at zero temperature, extending the original principle which becomes trivial as temperature approaches absolute zero.

Contribution

It introduces a universal bound on entropy change and heat dissipation that is valid at all temperatures, including zero, without assumptions on system state or interaction.

Findings

The new bound is tighter than Landauer's original at finite temperatures.

The bound remains non-trivial as temperature approaches zero.

It converges to the original Landauer bound at high temperatures.

Abstract

Landauer's bound relates changes in the entropy of a system with the inevitable dissipation of heat to the environment. The bound, however, becomes trivial in the limit of zero temperature. Here we show that it is possible to derive a tighter bound which remains non-trivial even as $T\to 0$. As in the original case, the only assumption we make is that the environment is in a thermal state. Nothing is said about the state of the system or the kind of system-environment interaction. Our bound is valid for all temperatures and is always tighter than the original one, tending to it in the limit of high temperatures.