Trapping atoms in the vacuum field of a cavity

Abstract

The aim of this work is to find ways to trap an atom in a cavity. In contrast to other approaches we propose a method where the cavity is basically in the vacuum state and the atom in the ground state. The idea is to induce a spatial dependent AC Stark shift by irradiating the atom with a weak laser field, so that the atom experiences a trapping force. The main feature of our setup is that dissipation can be strongly suppressed. We estimate the lifetime of the atom as well as the trapping potential parameters and compare our estimations with numerical simulations.

Forces between a Single Atom and Its Distant Mirror Image

“…[7,8]. It was also used in the proposals to trap an atom in a resonator [14,15] to which our experiment is closely related. Rigorously speaking, however, the vacuum field alone cannot account for spontaneous decay or its modification by reflectors, but radiation reaction must also contribute [23,24,25,26].…”

“…Forces due to applied light fields were first demonstrated experimentally by Lebedev [11], and the recoil of an absorbed photon on an atom was observed by Frisch who deflected an atomic beam with incoherent light [12]. With the advent of the laser, such forces have found many important applications, from decelerating, cooling and trapping atoms to optical tweezers in biology [13].Mirror-induced forces on individual atoms were first considered in connection with cavity-QED experiments, where their use has been proposed for trapping atoms in an optical resonator [14,15]. It is this kind of binding force which we observe in the experiment reported here.…”

Decoherence-free dynamical and geometrical entangling phase gates

“…As the evolution (13) can be used to create entanglement, we call it an entangling Raman (E-Raman) transition. In order to see how well the elimination of the dissipative states works, let us consider as an example the preparation of the maximally entangled state |A .…”

“…The scheme presented here involves two atoms trapped at fixed positions inside an optical cavity and can be implemented using the technology of the recent calcium ion experiment [12]. Alternatively, neutral atoms can be trapped with a standing laser field [13], as in the experiment by Fischer et al [14], or in an optical lattice [11,15]. In the last decade, several atom-cavity quantum computing schemes have been proposed [16][17][18][19][20][21][22][23][24], each of them having its respective merits.…”

Vacuum-field atom trapping in a wide aperture spherical resonator

“…A possible implementation could be to couple a light beam inside the cavity, and then to use the dipole force to hold the atoms in the right position, i.e., close to the cavity center. The effect of strong atom-cavity coupling on the dipole force has been studied theoretically [14,21], and very interesting effects can be expected : since the atomic relaxation will be modified by the cavity, the balance between the trapping and heating effects of the dipole trap will be changed with respect to free space, which could result in an improvement of the trap itself.…”