Measurement efficiency and n-shot read out of spin qubits

Abstract

We consider electron spin qubits in quantum dots and define a measurement efficiency e to characterize reliable measurements via n-shot read outs. We propose various implementations based on a double dot and quantum point contact (QPC) and show that the associated efficiencies e vary between 50% and 100%, allowing single-shot read out in the latter case. We model the read out microscopically and derive its time dynamics in terms of a generalized master equation, calculate the QPC current and show that it allows spin read out under realistic conditions.

5 pages, 1 figure

References in corpus (1)

• Zeeman energy and spin relaxation in a one-electron quantum dot

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