  The Rabi oscillations of a coupled spin-photon system are experimentally
studied using time domain microwave transmission measurements. An external
magnetic bias field is applied to control the amplitude and frequency of Rabi
oscillations, which are a measure of the coherent spin-photon energy exchange
and coupling strength respectively. The amplitude and frequency control is
described in the time domain as the transient response of a two-level
spin-photon system. This approach reveals the link between steady state and
transient behaviour of the cavity-magnon-polariton, which is necessary to
interpret time domain cavity-spintronic experiments. This transient model also
allows us to understand and quantify the polariton mode composition, which can
be controlled by the bias field.
