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arXiv · 0809.1511

Process tomography of field damping and measurement of Fock state lifetimes by quantum non-demolition photon counting in a cavity

M. Brune·J. Bernu·C. Guerlin·S. Deleglise·C. Sayrin·S. Gleyzes·S. Kuhr·I. Dotsenko·J. M. Raimond·S. Haroche
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Abstract

The relaxation of a quantum field stored in a high-$Q$ superconducting cavity is monitored by non-resonant Rydberg atoms. The field, subjected to repetitive quantum non-demolition (QND) photon counting, undergoes jumps between photon number states. We select ensembles of field realizations evolving from a given Fock state and reconstruct the subsequent evolution of their photon number distributions. We realize in this way a tomography of the photon number relaxation process yielding all the jump rates between Fock states. The damping rates of the $n$ photon states ($0\leq n \leq 7$) are found to increase linearly with $n$. The results are in excellent agreement with theory including a small thermal contribution.

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M. Brune, J. Bernu, C. Guerlin, S. Deleglise, C. Sayrin, S. Gleyzes, S. Kuhr, I. Dotsenko, J. M. Raimond, S. Haroche. 2008-09-09. Process tomography of field damping and measurement of Fock state lifetimes by quantum non-demolition photon counting in a cavity. https://doi.org/10.1103/physrevlett.101.240402

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