Speaker
Description
Superconducting qubits are one of the most promising platforms for universal quantum computing, yet they suffer from errors induced by interactions with their environment. In particular, radiation — both in the high-energy and infrared regimes — can break Cooper pairs in the superconductor and create Bogoliubov quasiparticles. Upon diffusing towards the Josephson junction, these quasiparticles can tunnel through its insulating barrier, causing energy and phase errors in the process. While this poses a challenge for the resilience of quantum computers, it simultaneously presents an opportunity to exploit this extreme environmental sensitivity for quantum sensing applications in fundamental physics.
In this talk, we will review our work on the interaction of infrared radiation with tantalum- and niobium-based superconducting qubits, as well as mitigation strategies. We will further present a setup employing a quantum cascade laser in the THz regime, designed to characterize the time-resolved response of our devices to infrared radiation bursts. This approach is useful both for studying qubit decay channels and for characterizing these devices as quasiparticle sensors.