Characterisation of spatial charge sensitivity in a multi-mode superconducting qubit
arXiv:2108.02105 · doi:10.1103/PhysRevApplied.17.024058
Abstract
Understanding and suppressing sources of decoherence is a leading challenge in building practical quantum computers. In superconducting qubits, low frequency charge noise is a well-known decoherence mechanism that is effectively suppressed in the transmon qubit. Devices with multiple charge-sensitive modes can exhibit more complex behaviours, which can be exploited to study charge fluctuations in superconducting qubits. Here we characterise charge-sensitivity in a superconducting qubit with two transmon-like modes, each of which is sensitive to multiple charge-parity configurations and charge-offset biases. Using Ramsey interferometry, we observe sensitivity to four charge-parity configurations and track two independent charge-offset drifts over hour timescales. We provide a predictive theory for charge sensitivity in such multi-mode qubits which agrees with our results. Finally, we demonstrate the utility of a multi-mode qubit as a charge detector by spatially tracking local-charge drift.
Main: 6 pages, 4 figures. Appendices: 3 pages, 3 figures, 1 table
References in corpus (10)
- Supplementary information for "Quantum supremacy using a programmable superconducting processor"
- Charge insensitive qubit design derived from the Cooper pair box
- Suppressing Charge Noise Decoherence in Superconducting Charge Qubits
- Tunable coupling in circuit quantum electrodynamics with a superconducting V-system
- A superconducting qubit with Purcell protection and tunable coupling
- Scqubits: a Python package for superconducting qubits
- Inductively shunted transmon qubit with tunable transverse and longitudinal coupling
- Suppressed crosstalk between two-junction superconducting qubits with mode-selective exchange coupling
- Saving superconducting quantum processors from qubit decay and correlated errors generated by gamma and cosmic rays
- Low frequency correlated charge noise measurements across multiple energy transitions in a tantalum transmon