Coherent internal state transfer by three-photon STIRAP-like scheme for many-atom samples

TL;DR

This paper proposes a three-photon STIRAP-like scheme for coherent state transfer in many-atom samples, achieving high fidelity and canceling Doppler shifts, with potential applications in quantum information processing.

Contribution

It introduces a novel three-photon resonance scheme for state transfer in alkaline-earth-metal ions, enhancing robustness against Doppler effects compared to traditional two-photon methods.

Findings

Achieves transfer fidelity of 1 - 8×10^{-5} with realistic parameters.

Demonstrates cancellation of first-order Doppler shifts in many-ion samples.

Extends scheme to synthesize superpositions of multiple states.

Abstract

A STIRAP-like scheme is proposed to exploit a three-photon resonance taking place in alkaline-earth-metal ions. This scheme is designed for state transfer between the two fine structure components of the metastable D-state which are two excited states that can serve as optical or THz qu-bit. The advantage of a coherent three-photon process compared to two-photon STIRAP lies in the possibility of exact cancellation of the first order Doppler shift which opens the way for an application to a sample composed of many ions. The transfer efficiency and its dependence with experimental parameters are analyzed by numerical simulations. This efficiency is shown to reach a fidelity as high as $(1-8.10^{-5})$ with realistic parameters. The scheme is also extended to the synthesis of a linear combination of three stable or metastable states.