A Non-Demolition Single Spin Meter

摘要

We present the theory of a single spin meter consisting of a quantum dot in amagnetic field under microwave irradiation combined with a charge counter. Weshow that when a current is passed through the dot, a change in the averageoccupation number occurs if the microwaves are resonant with the on-dot Zeemansplitting. The width of the resonant change is given by the microwave inducedRabi frequency, making the quantum dot a sensitive probe of the local magneticfield and enabling the detection of the state of a nearby spin. If the dot-spinand the nearby spin have different g-factors a non-demolition readout of thespin state can be achieved. The conditions for a reliable spin readout arefound.