Experimental investigation of long-lived Rydberg states in ultracold argon

Abstract

We report on our investigation of the formation and survival of long-lived Rydberg states in argon produced by pulsed laser excitation of ultracold metastable state argon atoms in a magneto-optical trap. The states studied have a 2 P 1/2 core. Low angular momentum Rydberg states with this core normally autoionize rapidly. If, however, atoms are excited in the presence of electric fields, higher angular momentum states, traditionally termed "ZEKE states" (ZEKE is derived from "zero kinetic energy") can be formed. The lifetime of these states can be orders of magnitude greater than low angular momentum states. In this paper, we report on the time dependence of ZEKE Rydberg state population in an ultracold environment.

Transition rates for a Rydberg atom surrounded by a plasma

“…Because of their macroscopic characters and long lifetimes, nowadays Rydberg states become a fundamental concept of open quantum systems in different fields of physics, such as quantum information research [10][11][12] and ultracold plasmas [13][14][15]. Recently the existence of Rydberg excitons in the copper oxide Cu 2 O [16] is demonstrated which enable visible measurements of coherent quantum effects [17].…”