Work

Observation of Discrete Charge States of a Coherent Two-Level System in a Superconducting Qubit

Year: 2024

Type: article

Abstract: We report observations of discrete charge states of a coherent two-level system (TLS) that is strongly coupled to an offset-charge-sensitive superconducting transmon qubit. We measure an offset charge of 0.072e associated with the two TLS eigenstates, which have a transition frequency of 2.9 GHz and a relaxation time exceeding 3 ms. Combining measurements in the strong dispersive and resonant regime, we quantify both transverse and longitudinal coupling of the TLS-qubit interaction. We further perform joint tracking of TLS transitions and quasiparticle tunneling dynamics but find no intrinsic correlations. This Letter demonstrates microwave-frequency TLS as a source of low-frequency charge noise.

Source: Physical Review Letters

DOI: 10.1103/physrevlett.133.160602

Authors: Bao-Jie Liu, Ying-Ying Wang, Tal Sheffer, Chen Wang

Institution: University of Massachusetts Amherst

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: green

Funders: U.S. Department of Energy, Office of Science, Lincoln Laboratory, Massachusetts Institute of Technology

Awards: G241279073, G357145406, G5765906131, G7463374569