The atomic clocks, whether operating at optical or microwave region, can be divided into two
categories according to their working mode, namely the passive clocks and active clocks …

Laser-cooled and quantum degenerate atoms are being pursued as quantum simulators
and form the basis of today's most precise sensors. A key challenge toward these goals is to …

Laser frequency noise contributes a significant limitation to today's best atomic clocks. A
proposed solution to this problem is to create a superradiant laser using an optical clock …

We propose a system for observing the correlated phase dynamics of two mesoscopic
ensembles of atoms through their collective coupling to an optical cavity. We find a …

Abstract In conventional Bardeen–Cooper–Schrieffer superconductors, electrons with
opposite momenta bind into Cooper pairs due to an attractive interaction mediated by …

Today's narrowest linewidth lasers are limited by mirror motion in the reference optical
resonator used to stabilize the laser's frequency. Recent proposals suggest that …

Quantum metrology protocols exploiting ensembles of N two-level systems and Ramsey-
style measurements are ubiquitous. However, in many cases excess readout noise severely …

We consider various approaches to the creation of a high-stability active optical frequency
standard, where the atomic ensemble itself produces a highly stable and accurate frequency …

An ideal superradiant laser on an optical clock transition of noninteracting cold atoms is
predicted to exhibit an extreme frequency stability and accuracy far below mHz-linewidth. In …

We investigate Ramsey spectroscopy performed on a synchronized ensemble of two-level
atoms. The synchronization is induced by the collective coupling of the atoms to a heavily …