  Magnetic sensing technology has found widespread application in industries as
diverse as transportation, medicine, and resource exploration. Such use cases
often require highly sensitive instruments to measure the extremely small
magnetic fields involved, relying on difficult to integrate Superconducting
Quantum Interference Device (SQUID) and Spin-Exchange Relaxation Free (SERF)
magnetometers. A potential alternative, nitrogen vacancy (NV) centers in
diamond, has shown great potential as a high sensitivity and high resolution
magnetic sensor capable of operating in an unshielded, room-temperature
environment. Transitioning NV center based sensors into practical devices,
however, is impeded by the need for high power RF excitation to manipulate
them. Here we report an advance that combines two different physical phenomena
to enable a highly efficient excitation of the NV centers: magnetoelastic drive
of ferromagnetic resonance (FMR) and NV-magnon coupling. Our work demonstrates
a new pathway to combine acoustics and magnonics that enables highly energy
efficient and local excitation of NV centers without the need for any external
RF excitation, and thus could lead to completely integrated, on-chip, atomic
sensors.
