Microscopic bath effects on noise spectra in semiconductor quantum dot qubits

• URL: http://arxiv.org/abs/2007.03689v2
• Date: Wed, 27 Jan 2021 17:50:02 GMT
• Title: Microscopic bath effects on noise spectra in semiconductor quantum dot qubits
• Authors: Seongjin Ahn, S. Das Sarma, J. P. Kestner
• Abstract summary: When a system is thermally coupled to only a small part of a larger bath, statistical fluctuations of the temperature 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.
• Score: 0.966840768820136
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• 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.

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