Identification of soft modes in amorphous Al$_{2}$O$_{3}$ via first-principles

Alexander C. Tyner; Joshuah T. Heath; Thue Christian Thann; Vincent P. Michal; Peter Krogstrup; Mark Kamper Svendsen; Alexander V. Balatsky

doi:10.1002/qute.202500170

arXiv · 2502.14823

Identification of soft modes in amorphous Al$_{2}$O$_{3}$ via first-principles

Alexander C. Tyner·Joshuah T. Heath·Thue Christian Thann·Vincent P. Michal·Peter Krogstrup·Mark Kamper Svendsen·Alexander V. Balatsky

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Abstract

Amorphous Al$_{2}$O$_{3}$ is a fundamental component of modern superconducting qubits. While amphorphous oxides offer distinct advantages, such as directional isotropy and a consistent bulk electronic gap, in realistic systems these compounds support two-level systems (TLSs) which couple to the qubit, expediting decoherence. In this work, we perform a first-principles study of amorphous Al$_{2}$O$_{3}$ and identify low-energy modes in the electronic and phonon spectra as a possible origin for TLSs.

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cond-mat.mes-hall cond-mat.dis-nn cond-mat.mtrl-sci quant-ph

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Alexander C. Tyner, Joshuah T. Heath, Thue Christian Thann, Vincent P. Michal, Peter Krogstrup, Mark Kamper Svendsen, Alexander V. Balatsky. 2025-02-20. Identification of soft modes in amorphous Al$_{2}$O$_{3}$ via first-principles. https://doi.org/10.1002/qute.202500170

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