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arXiv · 1703.04483

Beating the limits with initial correlations

Daniel Basilewitsch·Rebecca Schmidt·Dominique Sugny·Sabrina Maniscalco·Christiane P. Koch
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Abstract

Fast and reliable reset of a qubit is a key prerequisite for any quantum technology. For real world open quantum systems undergoing non-Markovian dynamics, reset implies not only purification, but in particular erasure of initial correlations between qubit and environment. Here, we derive optimal reset protocols using a combination of geometric and numerical control theory. For factorizing initial states, we find a lower limit for the entropy reduction of the qubit as well as a speed limit. The time-optimal solution is determined by the maximum coupling strength. Initial correlations, remarkably, allow for faster reset and smaller errors. Entanglement is not necessary.

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Daniel Basilewitsch, Rebecca Schmidt, Dominique Sugny, Sabrina Maniscalco, Christiane P. Koch. 2017-03-13. Beating the limits with initial correlations. https://doi.org/10.1088/1367-2630/aa96f8

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