"Transpinnor": A new giant magnetoresistive spin-valve device

Summary form only given. "Transpinnor", a new multifunctional active solid-state magneto-electronic device utilizing giant magnetoresistance (GMR) spin-valves, has been fabricated and investigated using closed-flux structures of metallic pseudo spin-valves and anti-ferromagnetic oxide exchange-biased bottom spin-valves. Figure 1 shows a single-input "transpinnor" as a modified Wheatstone bridge circuit composed of four GMR spin-valves whose resistances can be changed by magnetic fields from currents flowing in one or more overlaying striplines that are not resistively connected. A "transpinnor" can be used as a transformer that has flat response down to d.c., an amplifier, a differential amplifier, and as logic gates such as AND, OR, NOR, NOT, and XOR. Applications of "transpinnors" include non-volatile data storage, electronics, and logic for an all-metal GMR magnetic random access memory MRAM chip (SpinRAM). The patterned dual-input "transpinnor" differential amplifier shown in Fig. 2 has a voltage output of 2/spl sim/3 mV and a rise time of 14 /spl mu/s as shown in Fig. 3. "Transpinnors" can also be used as high current-drivers since this output loaded by a 1 /spl Omega/ resistor can supply 2/spl sim/3 mA for sensing or biasing of an integrated CMOS-MRAM chip. Indeed, a full SpinRAM memory chip can be designed and built using only GMR "transpinnors" for word selection, digit selection, and differential sense amplifiers.