NQCP Seminar - Takeaki Miyamura (Nakamura group @ UTokyo)

Toward Practical Quantum Communication between Superconducting Qubits with Hardware-Efficient Implementation 

Superconducting qubits are one of the leading platforms that can perform practical quantum computation. When scaling up the system, it is likely that we need quantum communication between remote qubits, for which itinerant single microwave photons are a natural medium. In this work, we demonstrate quantum state transfer and remote-entanglement generation between fixed-frequency transmon qubits. To make the scheme robust against variations in device parameters, we design broadband resonators composed of two-coupled coplanar-waveguide resonators, achieving a bandwidth of more than 100 MHz. Furthermore, to overcome photon loss, which is the major source of infidelity, we demonstrate a photon-loss detection protocol that can be realized with only a conventional qubit-resonator system. Our scheme does not require any tunable circuit elements, paving the way for hardware-efficient quantum communication.