Coherent Manipulation of Multilevel Atoms for Quantum Information Processing

TL;DR

This paper investigates efficient population transfer in atom-cavity systems using $$-pulses and adiabatic passage, revealing resonance-like properties and coherence transfer mechanisms relevant for quantum information processing.

Contribution

It introduces a simple analytical model explaining nonadiabatic transfer properties and explores coherence transfer in two-atom systems under adiabatic methods.

Findings

Adiabatic passage shows high transfer efficiency without large Rabi frequencies.

Resonance-like nonadiabatic properties enable effective transfer.

Symmetry conditions allow simplified analysis of two-atom coherence dynamics.

Abstract

In quantum information processing, quantum cavities play an important role by providing the mechanisms to transfer information between atom qubits and photon qubits, or to couple single atoms with the optical modes of the cavity field. We explore numerically the population transfer in an atom + cavity system by using the $\pi$-pulse and adiabatic passage methods. While the first method is very efficient transferring the atomic population for no radiative decay of the intermediate level, the second method shows very interesting nonadiabatic, resonance-like properties that can be used to achieve very large transfer efficiencies without needing very large Rabi frequencies or very long interaction times. We introduce a simple analytical model to explore the origin of these properties and describe "qualitatively" the power-law dependence of the failure probability on the product of the pulse amplitude and the interaction time. We also examine numerically the transfer of interatomic coherence in a two-atom + cavity system by using adiabatic methods. For some specific symmetry conditions, we show that the dynamics of the original system can be studied as the individual evolution of a symmetric and an antisymmetric system, interacting separately with the classical field and the cavity mode, but mutually exchanging the atomic coherence.