Year: 2018
Type: article
Abstract: 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.
Source: Nature Communications
Authors: Q. Ficheux, S. Jezouin, Z. Leghtas, B. Huard
Institutions: Lyon 1 Université, École Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Paris Sciences et Lettres, École Normale Supérieure - PSL, Sorbonne Université, Sorbonne Paris Cité, Laboratoire de Physique de l'ENS de Lyon, Laboratoire de Physique de l'Ecole Normale Supérieure, Université Paris Diderot, Institut national de recherche en sciences et technologies du numérique, Centre Automatique et Systèmes, QUANTIC: QUANTum Information Circuits, École Nationale Supérieure des Mines de Paris
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,152
OpenAlex ID: W2767948319