Ultrastrong coupling between light and matter has, in the past decade, transitioned from a
theoretical idea to an experimental reality. It is a new regime of quantum light–matter …

Recent experiments have demonstrated that light and matter can mix together to an extreme
degree, and previously uncharted regimes of light-matter interactions are currently being …

Quantum phase transitions (QPTs) are usually associated with many-body systems in the
thermodynamic limit when their ground states show abrupt changes at zero temperature with …

The Dicke model describes the coupling between a quantized cavity field and a large
ensemble of two‐level atoms. When the number of atoms tends to infinity, this model can …

Present protocols of criticality-enhanced sensing with open quantum sensors assume direct
measurement of the sensor and omit the radiation quanta emitted to the environment …

Quantum field theories are the cornerstones of modern physics, providing relativistic and
quantum mechanical descriptions of physical systems at the most fundamental level …

The quantum Rabi model describing the fundamental interaction between light and matter is
a cornerstone of quantum physics. It predicts exotic phenomena like quantum phase …

This article presents a review of recent developments on various aspects of the quantum
Rabi model. Particular emphasis is given on the exact analytic solution obtained in terms of …

Quantum light-matter systems at strong coupling are notoriously challenging to analyze due
to the need to include states with many excitations in every coupled mode. We propose a …

We propose a superconducting circuit to implement a two-photon quantum Rabi model in a
solid-state device, where a qubit and a resonator are coupled by a two-photon interaction …