Fast Recovery of Niobium-based Superconducting Resonators after Laser Illumination

TL;DR

This paper demonstrates that immersing niobium-based superconducting resonators in superfluid helium-4 significantly accelerates their recovery after optical illumination, enabling higher optical pulse rates for quantum technologies.

Contribution

It reveals that superfluid helium immersion enables three orders of magnitude faster recovery of superconducting resonators post-illumination, providing new insights into light-induced loss mechanisms.

Findings

Resonance recovery is three orders faster in superfluid helium than in vacuum.

Light-induced loss mechanisms include quasiparticle poisoning and pair-breaking.

Superfluid helium enhances rapid recovery of superconducting circuits.

Abstract

Interfacing superconducting microwave resonators with optical systems enables sensitive photon detectors, quantum transducers, and related quantum technologies. Achieving high optical pulse repetition is crucial for maximizing the device throughput. However, light-induced deterioration, such as quasiparticle poisoning, pair-breaking-phonon generation, and elevated temperature, hinders the rapid recovery of superconducting circuits, limiting their ability to sustain high optical pulse repetition rates. Understanding these loss mechanisms and enabling fast circuit recovery are therefore critical. In this work, we investigate the impact of optical illumination on niobium nitride and niobium microwave resonators by immersing them in superfluid helium-4 and demonstrate a three-order-of-magnitude faster resonance recovery compared to vacuum. By analyzing transient resonance responses, we provide insights into light-induced dynamics in these superconductors, highlighting the advantages of niobium-based superconductors and superfluid helium for rapid circuit recovery in superconducting quantum systems integrated with optical fields.