H-3-Photon, Spin, and Raman Echoes

S. Hartman

Byoung Seung HAM

Using double optical Raman rephasing, an inversion-free resonant Raman echo is studied in an inhomogeneously broadened spin ensemble of a solid medium, where the Raman optical field-excited spin coherence has a frozen propagation vector. Unlike photon echoes whose quantum memory application is strictly limited due to πrephasing pulse-induced population inversion causing quantum noises, the optical Raman field-excited spin echo is inherently silent owing to the frozen propagation vector. Thus, the doubly rephased Raman echo can be directly applied for quantum interface in a population inversion-free environment.

A. I. Alekseev, V N Beloborodov

The Raman photon echo (RPE) in atomic vapour, allowing for depolarising atomic collisions and hyperfine structure of the atomic levels, has been studied theoretically. A new method of determining the electronic and electronic nuclear relaxation rates of the multipole moments of gas atoms with nonzero nuclear spin using the RPE has been proposed. The RPE method also makes it possible to measure the derivatives of these relaxation rates with respect to the impurity gas pressure. A method of determining the energy separation between the hyperfine structure sublevels has been developed. This method is based on the quantum beats of the RPE intensity and may be used when the hyperfine splitting is less than the Doppler linewidth. A possibility of identifying the forbidden transitions in both the electronic and total angular momenta has been shown.

Sven R. Hartmann

The general technique of the excitation of a system into a linear superposition of states is reviewed. Recent results in ruby are presented together with a simple theory which predicts Raman echoes.

Vitali V. Samartsev