Harnessing dark states: coherent control in coupled cavity-Rydberg-atom systems

TL;DR

This paper investigates dark-state effects in coupled cavity-Rydberg-atom systems, revealing the structure and properties of dark states across different atom numbers and configurations, with implications for quantum information science.

Contribution

It provides a detailed analysis of dark states in multi-atom cavity-Rydberg systems using the arrowhead-matrix method, including realistic interaction considerations.

Findings

Identified the number and form of dark states for 2-4 atoms.

Proposed a method to experimentally characterize dark states.

Analyzed dark-state effects with position-dependent interactions.

Abstract

The dark-state effect, caused by destructive interference, not only is an important fundamental research topic in atomic physics and quantum optics, but also has wide potential application in quantum physics and quantum information science. Using the arrowhead-matrix method, here we study the dark-state effect in a coupled cavity-Rydberg-atom system, in which $N$ Rydberg atoms with the dipole-dipole interactions are coupled to a single-mode cavity field. We obtain the numbers and form of the dark states in certain excitation-number subspaces for the two-, three-, and four-atom cases, as well as in the single-excitation subspace for a general $N$-atom case. We also suggest to characterize the dark states by inspecting the populations of some specific quantum states, which can be detected in experiments. Furthermore, we analyze the dark-state effect in a realistic case, where both the atomic dipole-dipole interaction strengths and the atom-cavity-field coupling strengths depend on the position of the atoms. Our findings pave the way for studying dark-state physics and applications in the cavity-Rydberg-atom platform.