Abstract
We consider electron spin qubits in quantum dots and define a measurement efficiency to characterize reliable measurements via -shot readouts. We propose various implementations based on a double dot and a quantum point contact (QPC) and show that the associated efficiencies vary between 50% and 100%, allowing single-shot readout in the latter case. We model the readout microscopically and derive its time dynamics in terms of a generalized master equation, calculate the QPC current, and show that it allows spin readout under realistic conditions.
- Received 1 September 2003
DOI:https://doi.org/10.1103/PhysRevLett.93.106804
©2004 American Physical Society