Electrical control of spin dynamics in Bi$_{ \rm 2}$Se$_{ \rm 3}$ was investigated in ring-type interferometers. Aharonov-Bohm and Altshuler-Aronov-Spivak resistance oscillations against magnetic field, and Aharorov-Casher resistance oscillations against gate voltage were observed in the presence of a Berry phase of $\pi$. A very large tunability of spin precession angle by gate voltage has been obtained, indicating that Bi$_{ \rm 2}$Se$_{ \rm 3}$-related materials with strong spin-orbit coupling are promising candidates for constructing novel spintronic devices.
Categories: cond-mat.mes-hall