Massachusetts Institute of Technology

Christopher Michael McNally

John Francis Barry

Danielle Ann Braje

Linh M Pham

Hannah Anne Clevenson

Kerry Alexander Johnson

Carson Arthur Teale

Michael F O'Keeffe

Erik R Eisenach

A magnetometer containing a crystal sensor with solid-state defects senses the magnitude and direction of a magnetic field. The solid-state defects in the crystal sensor absorb microwave and optical energy to transition between several energy states while emitting light intensity indicative of their spin states. The magnetic field alters the spin-state transitions of the solid-state defects by amounts depending on the solid-state defects' orientations with respect to the magnetic field. The optical read out, reporting the spin state of an ensemble of solid-state defects from one particular orientation class, can be used to lock microwave signals to the resonances associated with the spin-state transitions. The frequencies of the locked microwave signals can be used to reconstruct the magnetic field vector.

Methods and apparatus for optically detecting magnetic resonance

Here we present a solid-state spin sensor with enhanced sensitivity. The enhanced sensitivity is achieved by increasing the T* dephasing time of the color center defects within the solid-state spin sensor. The T* dephasing time extension is achieved by mitigating dipolar coupling between paramagnetic defects within the solid-state spin sensor. The mitigation of the dipolar coupling is achieved by applying a magic-angle-spinning magnetic field to the color center defects. This field is generated by driving a magnetic field generator (e.g., Helmholtz coils) with phase-shifted sinusoidal waveforms from current source impedance-matched to the magnetic field generator. The waveforms may oscillate (and the field may rotate) at a frequency based on the precession period of the color center defects to reduce color center defect dephasing and further enhance measurement sensitivity.

Stationary magic angle spinning enhanced solid state spin sensor

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Cambridge, MA, United States of America

Christopher Michael McNally