Microscopic bath effects on noise spectra in semiconductor quantum dot qubits

Abstract

When a system is thermally coupled to only a small part of a larger bath, statistical fluctuations of the temperature (more precisely, the internal energy) of this "sub-bath" around the mean temperature defined by the larger bath can become significant. We show that these temperature fluctuations generally give rise to 1/f-like noise power spectral density from even a single two-level system. We extend these results to a distribution of fluctuators, finding the corresponding modification to the Dutta-Horn relation. Then we consider the specific situation of charge noise in silicon quantum dot qubits and show that recent experimental data [E. J. Connors, et al., Phys. Rev. B 100, 165305 (2019)] can be modeled as arising from as few as two two-level fluctuators, and accounting for sub-bath size improves the quality of the fit.

arXiv comment5 pages, 3 figures + supplementary material (8 pages)

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Cited by in corpus (10)

• Charge-noise spectroscopy of Si/SiGe quantum dots via dynamically-decoupled exchange oscillations
• Reducing charge noise in quantum dots by using thin silicon quantum wells
• Low disorder and high valley splitting in silicon
• Simulation of 1/f charge noise affecting a quantum dot in a Si/SiGe structure
• Decoherence induced by a sparse bath of two-level fluctuators: peculiar features of $1/f$ noise in high-quality qubits
• Understanding disorder in Silicon quantum computing platforms: Scattering mechanisms in Si/SiGe quantum wells
• Effects of Temperature Fluctuations on Charge Noise in Quantum Dot Qubits
• Interacting Two-Level Systems as a Source of 1/f Charge Noise in Quantum Dot Qubits
• Anisotropy with respect to the applied magnetic field of spin qubit decoherence times
• A generalized model of the noise spectrum of a two-level fluctuator in the presence of an electron subbath