- We developed a electronic quantum-bit (qubit) circuit, a computational base of a quantum computer, that can attain quantum coherence an order of magnitude longer than any previously reported quantum integrated circuits. A large-scale quantum computer has abilities to perform computation and store quantum information, which are impossible with a classical computer. The number of possible operations in a quantum computer is determined by its coherence time for which the state of the quantum computer maintains its quantum nature. In this paper, the improvement in the coherence time owes to our new three-dimensional (3D) circuit quantum electrodynamics (QED) architecture that uses wireless connection between the superconducting qubit and a three-dimensional superconducting cavity. This creates a clean environment for the qubit to achieve long coherence. Our work advances one big step towards realizing an electronic large-scale quantum computer with the improved
coherence demonstrated in our 3D technology.
