Itinerant phonons as carriers of quantum information

Heavily used in classical signal processing, surface acoustic waves (SAWs) have also been proposed as a means to coherently couple distant solid-state quantum systems. Several groups have already reported the coherent coupling of standing SAWs modes to superconducting qubits [1-4], opening the door to the control and detection of quantum phonon states [5]. In this talk, I will describe our work in coupling superconducting qubits to propagating SAWs. We can controllably release and capture individual itinerant photons, demonstrating that quantum state transfer as well as remote entanglement generation between superconducting qubits using phonons can be realized [6]. Going a step further, I will show how two-phonon entanglement can be generated and used to realize a fundamental quantum optics experiment, quantum erasure [7], using phonons [8].

[1] M. V. Gustafsson, et al, Science, 346, 207-211, 2014

[2] R. Manenti, et al, Phys. Rev. B, 93, 041411, 2016

[3] B. A. Moores, Phys. Rev. Lett., 120, 2018

[4] A. N. Bolgar, et al, Phys. Rev. Lett., 120, 2018

[5] K. J. Satzinger, et al, Nature 563, 60-61, 2018

[6] A. Bienfait, et al, Science, 364, 368-371, 2019

[7] M. O. Scully and K. Drühl, Phys. Rev. A 25, 2208, 1982

[8] A. Bienfait et al., Phys. Rev X 10, 021055, 2020