UC Davis

The investigation of microscopic nonequilibrium thermodynamic systems is a wide a varied field of study. While hard to pin down with one particular frame of reference, the technological importance of understanding what happens when small systems are driven out of equilibrium is undeniable. While it is theoretically possible to do most control processes without driving a system very far from an equilibrium state, it generally takes an inordinate amount of time to do so. Computing itself is the process of preserving, transforming and translating a physical system’s states though various nonequlibrium procedures in finite time; thus, the mechanical computers that we all rely on are, at a fundamental level, nanoscale nonequilibrium thermal systems. In the following, various properties of nonequilibrium systems are discussed with an eye towards useful operations in computing. In chapter 1 the issue is tackled from a historical perspective; we see that controlling information can have a cost even using only equilibrium considerations. Next, chapter 2 moves away from purely equilibrium considerations by considering the costs that come from operating in finite time. Chapter 3 reviews a suite of relatively recent equalities that extend arbitrarily far outside the regime of equilibrium, as well as introducing novel equalities and applications for these new results. Chapter 4 investigates the applicability and scope of the new results, and in doing so, reveals the connection between a class of highly nonequlibrium processes and the precision of currents within them. Finally, in chapter 5, this class of protocol is leveraged to design highly efficient devices that are capable of universal computation that operate on similar timescales of todays state of the art machines, but hold the promise of being 4 or 5 orders of magnitude more efficient energetically.