Negative Differential Resistance in a Double-Constriction Quantum Wire Structure

Abstract

In recent years, with continuing advances in submicron lithographic techniques, there has been an increasing interest in the development of electronic devices with quantum confinement of electronic states in two and all three spatial dimensions, usually referred to as quantum wires and quantum boxes or dots, respectively (Reed and Kirk, 1989). Two-dimensional quantum confinement can be achieved in a short split-gate field-effect transistor as demonstrated in recent experiments (Van Wees et al., 1988; Wharam et al., 1988). There, the split gate is used to pinch off the conduction channel of a high mobility two-dimensional electron gas. At low temperature, the conductance exhibited plateaus as a function of gate voltage associated with the change in the number of occupied subbands in the uniform quantum wire constriction. Conductance calculations using mode-matching techniques correlate to these experimental results (Szafer and Stone, 1989; Weisshaar et al., 1989).

The research was partially supported under the U.S. Office of Naval Research and Tektronix, Inc., Beaverton, oregon. J.L. acknowledges support from IBM, Essex Junction, Vermont.