Characterization of a two-transmon processor with individual single-shot qubit readout.

Research paper by A A Dewes, F R FR Ong, V V Schmitt, R R Lauro, N N Boulant, P P Bertet, D D Vion, D D Esteve

Indexed on: 10 Mar '12Published on: 10 Mar '12Published in: Physical review letters


We report the characterization of a two-qubit processor implemented with two capacitively coupled tunable superconducting qubits of the transmon type, each qubit having its own nondestructive single-shot readout. The fixed capacitive coupling yields the sqrt[iSWAP] two-qubit gate for a suitable interaction time. We reconstruct by state tomography the coherent dynamics of the two-bit register as a function of the interaction time, observe a violation of the Bell inequality by 22 standard deviations after correcting readout errors, and measure by quantum process tomography a gate fidelity of 90%.