Unusual decoherence in qubit measurements with a Bose-Einstein condensate

Abstract

We consider an electrostatic qubit located near a Bose-Einstein condensate (BEC) of noninteracting bosons in a double-well potential, which is used for qubit measurements. Tracing out the BEC variables we obtain a simple analytical expression for the qubit's density-matrix. The qubit's evolution exhibits a slow ($\propto 1/\sqrt{t}$) damping of the qubit's coherence term, which however turns to be a Gaussian one in the case of static qubit. This stays in contrast to the exponential damping produced by most classical detectors. The decoherence is, in general, incomplete and strongly depends on the initial state of the qubit.

5 pages, additional explanations related to experimental realization are added, typos corrected, Phys. Rev. A, in press

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Cited by in corpus (11)

• Retrieving qubit information despite decoherence
• A weak-coupling master equation for arbitrary initial conditions
• Qubit residence time measurements with a Bose-Einstein condensate
• Spin measurements and control of cold atoms using spin-orbit fields
• Dynamics for partially coherent Bose-Einstein condensates in double wells
• Anomalous decoherence and absence of thermalization in a photonic many-body system
• Decoherence in a quantum harmonic oscillator monitored by a Bose-Einstein condensate
• Quantum law of rare events for systems with Bose-Einstein statistics
• Chaotic dynamics of a Bose-Einstein condensate coupled to a qubit
• The role of inter-well tunneling strength on coherence dynamics of two-species Bose-Einstein condensates
• Quantum decoherence of an anharmonic oscillator monitored by a Bose-Einstein condensate