Ideal switching effect in periodic spin-orbit coupling structures

An ideal switching effect is discovered in a semiconductor nanowire with a spatially-periodic Rashba structure. Bistable `ON' and `OFF' states can be realized by tuning the gate voltage applied on the Rashba regions. The energy range and position of `OFF' states can be manipulated effectively by varying the strength of the spin-orbit coupling (SOC) and the unit length of the periodic structure, respectively. The switching effect of the nanowire is found to be tolerant of small random fluctuations of SOC strength in the periodic structure. This ideal switching effect might be applicable in future spintronic devices.