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

E. Stourm (1) , M. Lepers (2) , J. Robert (1) , S. Nic Chormaic (3) , K. Mølmer (4) , E. Brion (5, 6)

1 LPGP - Laboratoire de physique des gaz et des plasmas
2 ICB - Laboratoire Interdisciplinaire Carnot de Bourgogne
3 OIST - Okinawa Institute of Science and Technology Graduate University
4 Department of Physics and Astronomy [Aarhus]
5 LCAR - Laboratoire Collisions Agrégats Réactivité
6 Théorie (LCAR)

In this paper, we report on numerical calculations of the spontaneous emission rates and Lamb shifts of a $^{87}\text{Rb}$ atom in a Rydberg-excited state $\left(n\leq30\right)$ 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 atom-nanofiber interface for quantum optics and quantum information purposes.

Domaines: Physique Quantique [quant-ph]

E. Stourm, M. Lepers, J. Robert, S. Nic Chormaic, K. Mølmer, et al.. Spontaneous emission and energy shifts of a Rydberg rubidium atom close to an optical nanofiber. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2020, 101 (5), pp.052508. ⟨10.1103/PhysRevA.101.052508⟩. ⟨hal-02481944⟩