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.

arXiv comment5 pages, 1 figure

References in corpus (14)

• Quantum Computation with Quantum Dots
• Coherent manipulation of electronic states in a double quantum dot
• Few-Electron Quantum Dot Circuit with Integrated Charge Read-Out
• Zeeman energy and spin relaxation in a one-electron quantum dot
• Allowed and forbidden transitions in artificial hydrogen and helium atoms
• Measurements with a noninvasive detector and dephasing mechanism
• Quantum Dot as Spin Filter and Spin Memory
• Selective quantum evolution of a qubit state due to continuous measurement
• Differential Charge Sensing and Charge Delocalization in a Tunable Double Quantum Dot
• Continuous quantum measurement of two coupled quantum dots using a point contact: A quantum trajectory approach
• Detection of Single Spin Decoherence in a Quantum Dot via Charge Currents
• Single Spin Dynamics and Decoherence in a Quantum Dot via Charge Transport
• Single Spin Measurement using Single Electron Transistors to Probe Two Electron Systems
• Statistics and noise in a quantum measurement process

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