Charge Qubit Purification by an Electronic Feedback Loop

Abstract

We propose the manipulation of an isolated qubit by a simple instantaneous closed-loop feedback scheme in which a time-dependent electronic detector current is directly back-coupled into qubit parameters. As specific detector model we employ a capacitively coupled single-electron transistor. We demonstrate the stabilization of pure delocalized qubit states above a critical detector-qubit coupling. This electronic purification is independent of the initial qubit state and is accomplished after few electron jumps through the detector. Our simple scheme can be used for the efficient and robust initialization of solid-state qubits in quantum computational algorithms at arbitrary temperatures.

4 pages, 4 figures, supplementary material, with minor modifications to be published by PRL

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Cited by in corpus (14)

• Quantum feedback: theory, experiments, and applications
• Probing the power of an electronic Maxwell Demon
• Strong suppression of shot noise in a feedback-controlled single-electron transistor
• Feedback stabilization of pure states in quantum transport
• Detection of the relaxation rates of an interacting quantum dot by a capacitively coupled sensor dot
• Optimal Squeezing in the Resonance Fluorescence of Single Photon Emitters
• Delayed feedback control in quantum transport
• Coherent feedback control in quantum transport
• Reverse quantum state engineering using electronic feedback loops
• Fighting Decoherence by Feedback-controlled Dissipation
• Feedback-induced nonlinearity and superconducting on-chip quantum optics
• Optimal measurement-based feedback control for a single qubit: a candidate protocol
• Coherent control in quantum transport: amplification, filtering and switching at finite bias
• Feedback-charging a metallic island