2020/01/31 by Tanmoy Bera, Sourav Majumder, Sudhir Kumar Sahu +1
Engineering · Physics and Astronomy · #Charge qubit #Coupling (piping) #Flux qubit #Force Microscopy Techniques and Applications #Materials science #Mechanical and Optical Resonators #Optoelectronics #Phase qubit #Photonic and Optical Devices #Physics #Quantum #Quantum mechanics #Qubit #Resonator #Superconducting quantum computing #Transmon #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1038/s42005-020-00514-y
published as Commun Phys 4, 12 (2021) · 9 pages, 4 figures, Supplementary information included
arxiv created 2020/10/28 · openalex publication_date 2021/01/19 · arxiv updated 2021/01/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Abstract Control over the quantum states of a massive oscillator is important for several technological applications and to test the fundamental limits of quantum mechanics. Addition of an internal degree of freedom to the oscillator could be a valuable resource for such control. Recently, hybrid electromechanical systems using superconducting qubits, based on electric-charge mediated coupling, have been quite successful. Here, we show a hybrid device, consisting of a superconducting transmon qubit and a mechanical resonator coupled using the magnetic-flux. The coupling stems from the quantum-interference of the superconducting phase across the tunnel junctions. We demonstrate a vacuum electromechanical coupling rate up to 4 kHz by making the transmon qubit resonant with the readout cavity. Consequently, thermal-motion of the mechanical resonator is detected by driving the hybridized-mode with mean-occupancy well below one photon. By tuning qubit away from the cavity, electromechanical coupling can be enhanced to 40 kHz. In this limit, a small coherent drive on the mechanical resonator results in the splitting of qubit spectrum, and we observe interference signature arising from the Landau-Zener-Stückelberg effect. With improvements in qubit coherence, this system offers a platform to realize rich interactions and could potentially provide full control over the quantum motional states.