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arXiv · 2004.08188

Ramsey-biased spectroscopy of superconducting qubits under dispersion

Yan Zhang·Tiantian Huan·Ri-gui Zhou·Hou Ian
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Abstract

We proposed a spectroscopic method that extends Ramsey's atomic spectroscopy to detect the transition frequency of a qubit fabricated on a superconducting circuit. The method uses a multi-interval train of qubit biases to implement an alternate resonant and dispersive couplings to an incident probe field. The consequent absorption spectrum of the qubit has a narrower linewidth at its transition frequency than that obtained from constantly biasing the qubit to resonance while the middle dispersive evolution incurs only a negligible shift in detected frequency. Modeling on transmon qubits, we find that the linewidth reduction reaches 23% and Ramsey fringes are simultaneously suppressed at extreme duration ratio of dispersion over resonance for a double-resonance scheme. If the scheme is augmented by an extra resonance segment, a further 37% reduction can be achieved.

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Yan Zhang, Tiantian Huan, Ri-gui Zhou, Hou Ian. 2020-04-17. Ramsey-biased spectroscopy of superconducting qubits under dispersion. https://doi.org/10.1103/physreva.102.013710

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