arXiv:1106.3365 · Physical Review B
Tunable multiphoton Rabi oscillations in an electronic spin system
Sylvain Bertaina, Nickolas Groll, L. Chen, I. Chiorescu
Abstract
We report on multiphoton Rabi oscillations and controlled tuning of a multilevel system at room temperature ($S=5/2$ for Mn${}^{2+}$:MgO) in and out of a quasiharmonic level configuration. The anisotropy is much smaller than the Zeeman splittings, e.g., the six-level scheme shows only a small deviation from an equidistant diagram. This allows us to tune the spin dynamics by compensating for the cubic anisotropy with either a precise static-field orientation or a microwave field intensity. Using the rotating-frame approximation, the experiments are explained very well by both an analytical model and a generalized numerical model. The calculated multiphoton Rabi frequencies are in excellent agreement with the experimental data.