Two-photon transitions induced by a stochastic microwave field
R. Boscaino, Rosario N. Mantegna · Physical Review A · 1987
Two-photon processes induced by a stochastic field, frequency-modulated by a Gaussian noise, are experimentally investigated in a $S=\frac{1}{2}$ spin system at microwave frequency. The shape and the width of the power spectra of the second-order two-photon-induced response of the spin system are measured for wide ranges of the rms amplitude and of the correlation time of the frequency fluctuations of the driving field.