Room temperature Szilard cycle and entropy exchange at the Landauer limit in a dopant atom double quantum dot silicon transistor

Abstract

Room-temperature (RT) thermodynamics of a dopant-atom double quantum dot (DQD) silicon transistor are extracted using measurements of the dual gate charge stability diagram. Current traces corresponding to electron exchange in the Szilard one-electron gas 'Maxwell Demon' thermodynamic cycle are determined. Theoretical analysis, based on energy state shifts within the generalised DQD charge stability diagram, is used to map the Szilard cycle entropy exchange to the stability diagram. The restriction on the inter-QD coupling energy E m > kT, necessary to observe DQD operation, is inherently seen to satisfy the Landauer limit, kTln2, for the minimum energy consumption per cycle for 1 bit. Associated entropy flows are extracted and simulated using single-electron Monte Carlo equivalent circuit simulations, from 4.2 to 290 K. An entropy valley, tending to the Szilard limit minimum of -kln2, occurs at degeneracy between neighbouring electron states, with traces persisting to RT. Changes in gate cycle trajectory, device capacitance, and temperature are characterised to establish conditions for RT operation.