Device fabrication for investigating Maxwell's Demon at room-temperature using double quantum dot transistors in silicon

Maxwell's Demon and its development by Szilard to a single particle engine, probe the limits of the 2nd law of thermodynamics and demonstrate a link between entropy and information. With advances in nanofabrication techniques, these thought experiments are becoming feasible. Room temperature (RT) dual-gate double quantum dot (DQD) transistors have been fabricated using electron beam lithography and geometric oxidation. Measurements at RT have shown device operation, where hexagonal patterns have been extracted from the charge stability diagram. These patterns imply ideal underlying characteristics and have been simulated in the form of a series DQD transistor. The boundaries of hexagonal regions correspond to a one-electron exchange between the coupled QDs. Carefully defined gate voltage trajectories crossing these boundaries show the behaviour of Szilard's engine and an identical minimum entropy of −k_B ln 2. These results suggest that DQD devices, even those that operate at RT, can be used to investigate the limits of the 2nd law of thermodynamics.