three Stanford researchers proposed that a new state, called the quantum spin Hall effect, could be realized without applying an external magnetic field.
Since quantum wells in mercury telluride/cadmium telluride sheets can be readily fabricated, it is possible to experimentally test the theoretical predictions of Zhang, Bernevig and Hughes. A research group at the University of Würzburg in Germany, under the direction of Professor Laurens Molenkamp, is currently doing this.
If the theory pans out, the quantum spin Hall effect may eventually inspire room-temperature devices with new capabilities. Zhang notes the potential for getting around a well-known roadblock of the electronics industry, the dictum saying the number of transistors fitting on a computer chip will double every 18 months: ''Transistors built based on the quantum spin Hall effect are expected to dissipate far less heat compared to conventional transistors, thus paving the way for extending Moore's law.''
In fact, hoping to turn Zhang's vision into a commercial reality, the Microelectronics Advanced Research Corporation, a consortium of leading U.S. semiconductor companies, has started to fund his research on the quantum spin Hall effect.
quantum spin hall state