Precision localization of single atom via spontaneous emission in three dimensions

Abstract

We present a new scheme for high-efficiency three-dimensional (3D) atom localization in a three-level atomic system via spontaneous emission. Owing to the space-dependent atom-field interaction, the position probability distribution of the atom can be directly determined by measuring the spontaneous emission. It is found that, by properly varying the parameters of the system, the probability of finding the atom at a particular position can be almost 100 %. Our scheme opens a promising way to achieve high-precision and high-efficiency 3D atom localization, which provides some potential applications to spatially selective single-qubit phase gate, entangling gates, and quantum error correction for quantum information processing.

Dressed-state analysis of efficient three-dimensional atom localization in a ladder-type three-level atomic system

“…That is to say, in our present scheme, high-precision 3D atom localization can be achieved in a wide range of excited state population distribution. However, [36] has not discussed such results. Therefore, our scheme has more advantages than other schemes [33][34][35][36] for 3D atom localization.…”

“…To further improve the precision of 3D atom localization, we propose a scheme for realizing a high-precision method by measuring the population of the excited state in a ladder-type three-level atomic system. Although such atomic models have been used to realize 3D atom localization [36], we have provided a new way of achieving high-precision localization, and our proposal has more advantages over [36]. The major differences are obtained as follows.…”

“…First, our scheme is based on the measurement of the upper-level population via the interaction of the atoms with two laser fields as well as three mutually perpend icular standing-wave fields. However, the scheme of [36] is based on the measurement of spontaneous emission, which is difficult to carry out in practical experiments. The reason for this is that spontaneous emission is a random process, and the frequency of the spontaneously emitted photon is hard to control.…”

“…The reason for this is that spontaneous emission is a random process, and the frequency of the spontaneously emitted photon is hard to control. Moreover, it is impossible to measure the spontaneous emission spectrum in [36] due to the absence of the condition of spontaneous emission. Second, the atom can be completely localized in one subspace by adjusting the phase shifts of three perpendicular standing-wave fields with slightly different wavelengths, and the maximum probability of finding the atom in 3D space is increased by a factor of eight compared with the previous schemes [33,34].…”

“…That is to say, we have obtained a new way of achieving high-precision 3D atom localization. However, such similar proposals have not been used in [36]. Third, we have discussed how the excited population modifies the 3D atom localization behavior, and one finds that the precision of 3D atom localization almost remains unchanged as the value of the excited population increases.…”