Optimized mitigation of random-telegraph-noise dephasing by spectator-qubit sensing and control

Abstract

Spectator qubits (SQs) are a tool to mitigate noise in hard-to-access data qubits. The SQ, designed to be much more sensitive to the noise, is measured frequently, and the accumulated results used rarely to correct the data qubits. For the hardware-relevant example of dephasing from random telegraph noise, we introduce a Bayesian method employing complex linear maps which leads to a plausibly optimal adaptive measurement and control protocol. The suppression of the decoherence rate is quadratic in the SQ sensitivity, establishing that the SQ paradigm works arbitrarily well in the right regime.

5 pages and 3 figures. This is a companion letter to arXiv:2205.12566

References in corpus (7)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Quantum computational advantage using photons
• Robust dynamical decoupling for quantum computing and quantum memory
• Suppressing qubit dephasing using real-time Hamiltonian estimation
• Low-frequency noise as a source of dephasing of a qubit
• Decoherence in qubits due to low-frequency noise
• Greedy versus Map-based Optimized Adaptive Algorithms for random-telegraph-noise mitigation by spectator qubits

Cited by in corpus (12)

• Mid-circuit correction of correlated phase errors using an array of spectator qubits
• Resource-efficient digital characterization and control of classical non-Gaussian noise
• Crosstalk Attacks and Defence in a Shared Quantum Computing Environment
• Greedy versus Map-based Optimized Adaptive Algorithms for random-telegraph-noise mitigation by spectator qubits
• Surpassing spectator qubits with photonic modes and continuous measurement for Heisenberg-limited noise mitigation
• Quantifying environment non-classicality in dissipative open quantum dynamics
• Quantum decoherence dynamics in stochastically fluctuating environments
• Recovery With Incomplete Knowledge: Fundamental Bounds on Real-Time Quantum Memories
• Quantum-network nodes with real-time noise mitigation using spectator qubits
• Imperfection analyses for random-telegraph-noise mitigation using spectator qubits
• Efficient learning and optimizing non-Gaussian correlated noise in digitally controlled qubit systems
• Photon counting statistics in the presence of spectral diffusion induced by nonequilibrium environmental fluctuations