Electrically detected single-spin resonance with quantum spin Hall edge states

Detection is most often the main impediment to reduce the number of spins in paramagnetic resonance experiments. Here, we propose another 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 Q, the spin relaxation, and decoherence times T1, and we discuss the feasibility of this experiment with state-of-the-art instrumentation.