Readout failures in superconducting qubits due to TLS-defects in tunnel junctions

Transmon is a superconducting qubit approach for quantum computing hardware. Source: latex text.

Abstract

Material defects give rise to parasitic two-level systems (TLS) which present a major source of decoherence in superconducting qubits. Here, we study a strongly coupled TLS that resides in the tunnel barrier of transmon qubit. We use multi-photon spectroscopy and TLS strain tuning to explore the rich spectrum of the interacting three-partite system consisting of TLS, qubit, and its readout resonator. This reveals a strong effective resonant coupling between the TLS and the qubit’s readout resonator which dresses the resonator states and results in a resonance frequency shift that spoils the readout signal. Our finding presents yet another way how material defects can interfere with qubit operation and hinder the realization of solid-state quantum processors.

Key Findings

Links

• Journal: arXiv preprint
• arXiv: 2605.02755

Verification Report

Verification status: verified. Disputes resolved: 0. Citation count snapshot (Semantic Scholar): 0. Ingestion source: latex. Text truncated: no.