  By connecting light to magnetism, cavity-magnon-polaritons (CMPs) can build
links from quantum computation to spintronics. As a consequence, CMP-based
information processing devices have thrived over the last five years, but
almost exclusively been investigated with single-tone spectroscopy. However,
universal computing applications will require a dynamic control of the CMP on
demand and within nanoseconds. In this work, we perform fast manipulations of
the different CMP modes with independent but coherent pulses to the cavity and
magnon system. We change the state of the CMP from the energy exchanging beat
mode to its normal modes and further demonstrate two fundamental examples of
coherent manipulation: First, a dynamic control over the appearance of
magnon-Rabi oscillations, i.e., energy exchange, and second, a complete energy
extraction by applying an anti-phase drive to the magnon. Our results show a
promising approach to control different building blocks for a quantum internet
and pave the way for further magnon-based quantum computing research.
