Aharonov-Bohm-Casher ring dot as a flux-tunable resonant tunneling diode

A mesoscopic ring subject to the Rashba spin-orbit interaction and sequentially coupled to an interacting quantum dot, in the presence of an Aharonov-Bohm flux, is proposed as a flux-tunable tunneling diode. The analysis of the conductance by means of the nonequilibrium Green's function technique shows an intrinsic bistability at varying Aharonov-Bohm flux when 2U > pi Gamma, where U is the charging energy on the dot and Gamma is the effective resonance width. The bistability properties are discussed in connection with spin-switch effects and logical storage device applications.