High performance bipolar spin transistor

In this article we demonstrate high performance giant magneto resistive spin transistor (GMRST) and magneto tunneling resistive spin transistor (MTRST) which base on the technologies of giant magneto resistance (GMR) and tunneling magneto resistance (TMR) effects. A p-n junction whose leakage is less than a Schottky diode is used as a potential barrier to select spin electrons. In case of GMRST the collector current, I/sub c/ varies from 95 /spl mu/A at magnetically parallel state to 2.6 /spl mu/A at magnetically anti-parallel state and gives a percentage change of more than 3400% at 77K. For the same magnetic states at room temperature the change reduces to about 53.4% with I/sub c/ varies from 213/spl mu/A to 138.8/spl mu/A. As for the MTRST, the change of I/sub c/ is about 45% at room temperature with current varies from 29/spl mu/A to 42/spl mu/A. The transfer ratio of these two spin devices increases as emitter bias is increased; however, higher emitter current does not benefit the change of magneto current. Memory effect which is the intrinsic behavior of magnetic phenomena is also demonstrated.