The recent progress in direct active cooling of the quantum‐electric degrees of freedom in
engineered circuits, or quantum‐circuit refrigeration is reviewed. In 2017, the discovery of a …

The initialization of superconducting qubits is one of the essential techniques for the
realization of quantum computation. In previous research, initialization above 99% fidelity …

We present here our recent results on qubit reset scheme based on a quantum-circuit
refrigerator (QCR). In particular, we use the photon-assisted quasiparticle tunneling through …

We experimentally demonstrate a recently proposed single-junction quantum-circuit
refrigerator (QCR) as an in situ tunable low-temperature environment for a superconducting …

In microwave quantum optics, dissipation usually corresponds to quantum jumps, where
photons are lost one by one. Here we demonstrate a new approach to dissipation …

We propose a quantum-circuit refrigerator (QCR) based on photon-assisted quasiparticle
tunneling through a single normal-metal–insulator–superconductor (NIS) junction. In …

Previous studies of photon-assisted tunneling through normal-metal–insulator–
superconductor junctions have exhibited potential for providing a convenient tool to control …

We experimentally demonstrate the fast generation of thermal states of a transmon using a
single-junction quantum-circuit refrigerator (QCR) as an in-situ-tunable environment …

Achieving fast and precise initialization of qubits is a critical requirement for the successful
operation of quantum computers. The combination of engineered environments with all …

The standard weak-coupling approximations associated to open quantum systems have
been extensively used in the description of a two-level quantum system, qubit, subjected to …