Electrically-detected single-spin resonance with Quantum Spin Hall edge states

Abstract

Detection is most often the main impediment to reduce the number of spins in paramagnetic resonance experiments. Here we propose a new route to carry out electrically-detected spin resonance of an individual spin, placed at the edge of a quantum spin Hall insulator (QSHI). The edges of a QSHI host a one dimensional electron gas with perfect spin-momentum locking. Therefore, the spin relaxation induced by emission of an electron-hole pair at the edge state of the QSHI can generate current. Here we demonstrate that driving the system with an AC signal, a nonequilibrium occupation can be induced in the absence of applied bias voltage, resulting in a DC measurable current. We compute the DC current as a function of the Rabi frequency Ω, the spin relaxation and decoherence times, T1 and we discuss the feasibility of this experiment with state of the art instrumentation.