Quantum-mechanical effects at the macroscopic level were first explored in Josephson-
junction-based superconducting circuits in the 1980s. In recent decades, the emergence of …

We present an overview of recent advances in the study of energy dynamics and
mechanisms for energy conversion in qubit systems with special focus on realizations in …

The performance of a wide range of quantum computing algorithms and protocols depends
critically on the fidelity and speed of the employed qubit readout. Examples include gate …

High-fidelity and rapid readout of a qubit state is key to quantum computing and
communication, and it is a prerequisite for quantum error correction. We present a readout …

Coupling a resonator to a superconducting qubit enables various operations on the qubit,
including dispersive readout and unconditional reset. The speed of these operations is …

Currently available quantum processors are dominated by noise, which severely limits their
applicability and motivates the search for new physical qubit encodings. In this work, we …

Fast, high-fidelity, and quantum nondemolition (QND) qubit readout is an essential element
of quantum information processing. For superconducting qubits, state-of-the-art readout is …

While the squeezing of a propagating field can, in principle, be made arbitrarily strong, the
cavity-field squeezing is subject to the well-known 3 dB limit, and thus has limited …

It has been a long-standing goal to improve dispersive qubit readout with squeezed light.
However, injected external squeezing (IES) cannot enable a practically interesting increase …

Cat qubits, for which logical| 0⟩ and| 1⟩ are coherent states|±α⟩ of a harmonic mode, offer
a promising route towards quantum error correction. Using dissipation to our advantage so …