Micro electro-mechanical logic device at fundamental energy limit

Abstract

In 1961 Landauer argued that reset a bit of information requires a minimum energy expenditure of k B T ln 2. This quantity is directly related to the entropy reduction in the system. This famous claim was then extended to all logic operations when the entropy at the inputs is larger than the entropy at the outputs, i.e. logically irreversible operations. However, in certain situations, a reduction of information in terms of input/output does not lead to a reduction of the physical entropy in the device. In this article we show the implementation of a storage unit and a logic gate with a micro-electro-mechanical device and measure the energy dissipated during their operation. We show that while an entropy reduction in the device implies a finite heat production, logic irreversibility it is not always associated with physical irreversibility.