Journal Article 1 Mention
Measurements of Macroscopic Quantum Tunneling out of the Zero-Voltage State of a Current-Biased Josephson Junction
Michel Devoret1985
John M. MartinisJohn Clarke
Top 5% · 95th percentile
409 citations · Atomic and Molecular Physics, and Optics

Summary

1 Sample Definition And Size

The study investigated an underdamped (quality factor Q ≈ 30) current‑biased Josephson junction. The sample size refers to the single junction studied; no meta‑analysis or multiple samples were reported.

2 Study Type

Experimental observational study measuring the escape rate from the zero‑voltage state of a Josephson junction, comparing thermal activation and macroscopic quantum tunneling regimes.

3 Conflicts Of Interest

No conflicts of interest are declared in the available metadata.

4 Results Summary

The escape rate of the underdamped Josephson junction was measured as a function of bias current and via resonant activation with microwaves in the thermal regime. At low temperatures, the escape rate became temperature‑independent and matched the zero‑temperature theoretical prediction for macroscopic quantum tunneling with no adjustable parameters.

Abstract

The escape rate of an underdamped ($Q\ensuremath{\approx}30$), current-biased Josephson junction from the zero-voltage state has been measured. The relevant parameters of the junction were determined in situ in the thermal regime from the dependence of the escape rate on bias current and from resonant activation in the presence of microwaves. At low temperatures, the escape rate became independent of temperature with a value that, with no adjustable parameters, was in excellent agreement with the zero-temperature prediction for macroscopic quantum tunneling.

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