Multiplexed photon number measurement
Abstract
When a two-level system -- a qubit -- is used as a probe of a larger system, it naturally leads to answering a single yes-no question about the system state. Here we propose a method where a single qubit is able to extract, not a single, but many bits of information about the photon number of a microwave resonator using continuous measurement. We realize a proof-of-principle experiment by recording the fluorescence emitted by a superconducting qubit reflecting a frequency comb, thus implementing multiplexed photon counting where the information about each Fock state -- from 0 to 8 -- is simultaneously encoded in independent measurement channels. Direct Wigner tomography of the quantum state of the resonator evidences the back-action of the measurement as well as the optimal information extraction parameters. Our experiment unleashes the full potential of quantum meters by replacing a sequential quantum measurements with simultaneous and continuous measurements separated in the frequency domain.
Cite
@article{arxiv.2001.03217,
title = {Multiplexed photon number measurement},
author = {Antoine Essig and Quentin Ficheux and Théau Peronnin and Nathanaël Cottet and Raphaël Lescanne and Alain Sarlette and Pierre Rouchon and Zaki Leghtas and Benjamin Huard},
journal= {arXiv preprint arXiv:2001.03217},
year = {2021}
}
Comments
This new version of the manuscript adds several results compared to the first versions