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Coupled Ito equations of continuous quantum state measurement, and estimation

Lajos Diosi·Thomas Konrad·Artur Scherer·Juergen Audretsch
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Abstract

We discuss a non-linear stochastic master equation that governs the time-evolution of the estimated quantum state. Its differential evolution corresponds to the infinitesimal updates that depend on the time-continuous measurement of the true quantum state. The new stochastic master equation couples to the two standard stochastic differential equations of time-continuous quantum measurement. For the first time, we can prove that the calculated estimate almost always converges to the true state, also at low-efficiency measurements. We show that our single-state theory can be adapted to weak continuous ensemble measurements as well.

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Lajos Diosi, Thomas Konrad, Artur Scherer, Juergen Audretsch. 2006-09-15. Coupled Ito equations of continuous quantum state measurement, and estimation. https://doi.org/10.1088/0305-4470/39/40/l01

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