Contents

Landauer’s Principle relates entropy decrease and heat dissipation during logically irre-versible processes. Most theoretical justifications of Landauer’s Principle either use thermo-dynamic reasoning or rely on specific models based on arguable assumptions. Here, we aim at a general and minimal setup to formulate Landauer’s Principle in precise terms. We pro-vide a simple and rigorous proof of an improved version of the Principle, which is formulated in terms of an equality rather than an inequality. The proof is based on quantum statistical physics concepts rather than on thermodynamic argumentation. From this equality version, we obtain explicit improvements of Landauer’s bound that depend on the effective size of the thermal reservoir and reduce to Landauer’s bound only for infinite-sized reservoirs