Multiple-valued logic application of a triple well resonant tunneling diode

A novel resonant tunneling diode (RTD) with four potential barriers and three quantum wells has been proposed and applied to multiple-valued logic devices. This is the first report of a single diode exhibiting significant double negative differential resistance (NDR) characteristics and operating as a triply stable device with a single supply voltage. The structure of the device is described. It showed significant double NDR between 180 K and room temperature, exhibiting the best characteristics at 219 K; peak/valley current ratios were 2.8 and 1.4 with the same peak currents of 4*10/sup 2/ A/cm/sup 2/ for both NDR peaks. With load resistance of 100 Omega and applied voltage of 1 V, this diode exhibited three stable states at 0.066, 0.158, and 0.249 V, in excellent agreement with numerically simulated values. The numerical simulation also showed that the two resonance voltages can be adjusted independently by varying the width of the wells. This triple-well RTD can realize triple-valued logic devices with a single supply voltage. >