The Cost of Erasing Information

Abstract

Landauer has argued that the process of erasing 1 bit of information requires a minimum amount of work equal to kT ln(2) where T is the temperature of a thermal reservoir that consumes the entropy of the bit. We show that, in principle, the thermal reservoir can be replaced by a reservoir of N spin-1/2 particles which is subject to the conservation of spin angular momentum. The cost of erasing 1 bit of information in this case is found to be in terms of the z component of spin angular momentum.