Compare Papers

Paper 1

Unconventional geometric quantum computation robust to residual crosstalk in a superconducting circuit

Ying Hong, Fei-Fan Cui, Li-Na Ji, Zheng-Yuan Xue, Tao Chen

Year

2024

Journal

Physical Review Applied

DOI

10.1103/physrevapplied.22.064095

arXiv

-

No abstract.

Open paper

Paper 2

Dynamics of a qubit while simultaneously monitoring its relaxation and dephasing

Q. Ficheux, S. Jezouin, Z. Leghtas, B. Huard

Year

2017

Journal

arXiv preprint

DOI

arXiv:1711.01208

arXiv

1711.01208

Decoherence originates from the leakage of quantum information into external degrees of freedom. For a qubit the two main decoherence channels are relaxation and dephasing. Here, we report an experiment on a superconducting qubit where we retrieve part of the lost information in both of these channels. We demonstrate that raw averaging the corresponding measurement records provides a full quantum tomography of the qubit state where all three components of the effective spin-1/2 are simultaneously measured. From single realizations of the experiment, it is possible to infer the quantum trajectories followed by the qubit state conditioned on relaxation and/or dephasing channels. The incompatibility between these quantum measurements of the qubit leads to observable consequences in the statistics of quantum states. The high level of controllability of superconducting circuits enables us to explore many regimes from the Zeno effect to underdamped Rabi oscillations depending on the relative strengths of driving, dephasing and relaxation.

Open paper