July 18, 2024
ABSTRACT: Counting the number of photons in an electromagnetic mode is an important tool for quantum information processing. In order to perform a single shot measurement, one usually encodes information about the photon number into a qubit state and read out the qubit. Repeating this procedure while varying the encoded single bit of information enables to pinpoint the number of photons. In this talk, I will present two experiments that address two main challenges in photocounting. First, I will show how one can avoid the sequential repetition of qubit measurements and instead use a single superconducting qubit in order to multiplex the measurement of the photon number in a stationary microwave mode. Second, I will show how we could convert a stationary mode counter into a photocounter of traveling wave packets using a quantum memory. RELATED PAPERS [1] Multiplexed photon number measurement A. Essig, Q. Ficheux, T. Peronnin, N. Cottet, R. Lescanne, A. Sarlette, P. Rouchon, Z. Leghtas, B. Huard https://arxiv.org/abs/2001.03217 [2] Number-resolved photocounter for propagating microwave mode R. Dassonneville, R. Assouly, T. Peronnin, P. Rouchon, B. Huard https://arxiv.org/abs/2004.05114