Spontaneous emission of a sodium Rydberg atom close to an optical nanofibre

Abstract

In this paper, we report on numerical calculations of the spontaneous emission rates and Lamb shifts of a 87 Rb atom in a Rydberg-excited state (n ≤ 30) located close to a silica optical nanofiber. We investigate how these quantities depend on the fiber's radius, the distance of the atom to the fiber, the direction of the atomic angular momentum polarization as well as the different atomic quantum numbers. We also study the contribution of quadrupolar transitions, which may be substantial for highly polarizable Rydberg states. Our calculations are performed in the macroscopic quantum electrodynamics formalism, based on the dyadic Green's function method. This allows us to take dispersive and absorptive characteristics of silica into account; this is of major importance since Rydberg atoms emit along many different transitions whose frequencies cover a wide range of the electromagnetic spectrum. Our work is an important initial step towards building a Rydberg atomnanofiber interface for quantum optics and quantum information purposes.

Spontaneous emission and energy shifts of a Rydberg rubidium atom close to an optical nanofiber

“…The strongest effect is obtained for S and D states, as already noted and interpreted in Ref. [27]. As R increases, the guided modes are (quasi)exponentially damped, hence the damping of g itself.…”

“…In the perspective of building a quantum network based on Rydberg-blockaded atomic ensembles linked via an optical nanofiber, we recently studied the spontaneous emission of a highly excited (Rydberg) sodium atom in the neighborhood of an optical nanofiber made of silica [27]. To be more specific, we investigated how the atomic emission rates into the guided and radiative fiber modes are influenced by the radius of the fiber, the distance of the atom to the fiber, and the symmetry of the Rydberg state.…”

“…This forced us, in Ref. [27], to restrict ourselves to Rydberg levels of moderate principal numbers so that the frequencies of the transitions involved remain in a nondispersive and nonabsorptive window of the silica spectrum. By contrast, here we resort to the framework of macroscopic quantum electrodynamics based on the dyadic Green's function [29,30].…”

Generation of cold Rydberg atoms at submicron distances from an optical nanofiber

“…In addition, atoms in the evanescent field region are intrinsically coupled to an optical bus in the form of the fiber-guided mode. This can lead to low-loss transfer of information to and from the interaction region [24], a prerequisite for Rydberg-based quantum repeaters in fibercoupled cavities [25].…”

Non-contact detection of nanoscale structures using optical nanofiber

“…Due to these properties, nanofibers are used as efficient input-output ports for optical microcavities [7,8]. They have also been employed to efficiently couple fluorescence from single-light emitters to single-mode fibers [9][10][11][12][13][14][15][16]. In addition, nanofibers have been used in the generation of supercontinuum [17], two-photon excited fluorescence [18], and more recently in optical tweezers [19].…”