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arXiv · 2605.20652

WSi weak link element with a non-sinusoidal current-phase relation

Sarah Garcia Jones·Trevyn F. Q. Larson·Sai Pavan Chitta·Heli Vora·Varun Verma·Sae Woo Nam·José Aumentado·Jens Koch·Raymond W. Simmonds·András Gyenis
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Abstract

Nonlinearity is an essential ingredient for encoding quantum states with non-uniform energy spacing, implementing coherent quantum gates, reading out qubits, amplifying, and mixing electromagnetic signals. In this work, we demonstrate the nonlinear behavior of a constriction fabricated from an amorphous, high-kinetic inductance material, tungsten silicide, embedded in a three-dimensional RF-SQUID. We find that the results are consistent with the weak link behaving as a Josephson junction with a sawtooth-like current-phase relation or a quantum phase slip element. Finally, we measure relaxation times of the metastable, persistent-current states trapped in the local minima of the potential.

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Sarah Garcia Jones, Trevyn F. Q. Larson, Sai Pavan Chitta, Heli Vora, Varun Verma, Sae Woo Nam, José Aumentado, Jens Koch, Raymond W. Simmonds, András Gyenis. 2026-05-20. WSi weak link element with a non-sinusoidal current-phase relation. https://arxiv.org/abs/2605.20652

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