Heat generation required by information erasure

Landauer argued that the erasure of 1 bit of information stored in a memory device requires a minimal heat generation of ${\mathit{k}}_{\mathit{B}}$T ln2 [IBM J. Res. Dev. 5, 183 (1961)], but recently several articles have been written to dispute the validity of his argument. In this paper, we deal with a basic model of the memory, that is, a system including a particle making the Brownian motion in a time-dependent potential well, and show that Landauer’s claim holds rigorously if the random force acting on the particle is white and Gaussian. Our proof is based on the fact that the analogue of the second law of thermodynamics dQ≤${\mathit{k}}_{\mathit{B}}$TdS holds rigorously by virtue of the Fokker-Planck equation, even if the potential is not static. Using the above result, we also discuss the counterargument of Goto et al. to Landauer’s claim based on the quantum flux parametron.