Using stochastic resonance of two-level systems to increase qubit decoherence times

TL;DR

This paper proposes using stochastic resonance induced by oscillating fields to shift TLS noise spectra, thereby increasing qubit coherence times and enabling detailed investigation of TLS properties.

Contribution

It introduces a novel method to mitigate TLS-induced dephasing and to probe TLS physical characteristics using qubit spectroscopy.

Findings

Stochastic resonance shifts TLS noise to higher frequencies.

This shift increases qubit dephasing times.

Qubit spectroscopy can reveal TLS dephasing rates and energy levels.

Abstract

Two-level systems (TLS) are the major source of dephasing of spin qubits in numerous quantum computing platforms. In spite of much effort, it has been difficult to substantially mitigate the effects of this noise or, in many cases, to fully understand its physical origin. We propose a method to make progress on both of these issues. When an oscillating field is applied to a TLS, stochastic resonance can occur and the noise spectrum is moved to higher frequencies. This shift in the TLS noise spectrum will increase the dephasing times of the qubits that they influence. Furthermore, the details of this effect depend on the physical properties of the noise sources. Thus one can use qubit spectroscopy to investigate their physical properties, specifically the extent to which the TLS themselves possess quantum coherence. We find that it should be possible to determine the dephasing rate and the energy level separation of the TLS themselves in this way.