On computing with locally-interconnected architectures in atomic/nanoelectronic systems

The past decade has seen tremendous experimental and theoretical progress in the field of mesoscopic devices and molecular self assembly techniques, leading to laboratory demonstration of many new device concepts. While these studies have been important from a fundamental physics perspective, it has been recognized by many that they may offer new insights into building a future generation of computing machines. This has recently led to a number of proposals for computing machines which use these new and novel device concepts. In this paper, we explain the physical principles behind the operation of one of these proposals, namely the ground state computing model. These computational models share some of the characteristics of the well-known systolic type processor arrays, namely spatial locality, and functional uniformity. In particular, we study the effect of metastable states on the relaxation process (and hence information propagation) in locally coupled and boundary-driven structures. We first give a general argument to show that metastable states are inevitable even in the simplest of structures, a wire. At finite temperatures, the relaxation mechanism is a thermally assisted random walk. The time required to reach the ground state and its life time are determined by the coupling parameters. These time scales are studied in a model based on an array of quantum dots.