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arXiv · 2210.09718

Resolving Fock states near the Kerr-free point of a superconducting resonator

Yong Lu·Marina Kudra·Timo Hillmann·Jiaying Yang·Hangxi Li·Fernando Quijandría·Per Delsing
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Abstract

We have designed a tunable nonlinear resonator terminated by a SNAIL (Superconducting Nonlinear Asymmetric Inductive eLement). Such a device possesses a sweet spot in which the external magnetic flux allows to suppress the Kerr interaction. We have excited photons near this Kerr-free point and characterized the device using a transmon qubit. The excitation spectrum of the qubit allows to observe photon-number-dependent frequency shifts about nine times larger than the qubit linewidth. Our study demonstrates a compact integrated platform for continuous-variable quantum processing that combines large couplings, considerable relaxation times and excellent control over the photon mode structure in the microwave domain.

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Yong Lu, Marina Kudra, Timo Hillmann, Jiaying Yang, Hangxi Li, Fernando Quijandría, Per Delsing. 2022-10-18. Resolving Fock states near the Kerr-free point of a superconducting resonator. https://arxiv.org/abs/2210.09718

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