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Cavity-enhanced room-temperature magnetometry using absorption by nitrogen-vacancy centers in diamond
K Jensen1, N Leefer1, A Jarmola1
1Department of Physics, University of California, Berkeley, California 94720-7300, USA.
Physical Review Letters
|May 13, 2014
Summary
We developed a room-temperature magnetic field sensor using nitrogen-vacancy centers in diamond. This cavity-enhanced sensor achieves high sensitivity for detecting magnetic fields.
Area of Science:
- Quantum Sensing
- Materials Science
- Optics and Photonics
Background:
- Nitrogen-vacancy (NV) centers in diamond are promising solid-state qubits for quantum sensing applications.
- Existing NV-based sensors often require cryogenic temperatures or complex optical setups for high sensitivity.
- Enhancing light absorption in NV-diamond systems is crucial for improving sensor performance.
Purpose of the Study:
- To demonstrate a highly sensitive, room-temperature magnetic field sensor utilizing NV centers in diamond.
- To leverage optical cavities to enhance light absorption for improved magnetic resonance detection.
- To project the ultimate sensitivity limits of the developed sensor.
Main Methods:
- Fabrication of a diamond sample containing nitrogen-vacancy centers.
- Integration of the diamond into an external optical cavity to enhance light absorption.
- Detection of magnetic resonance via absorption of 1042 nm light resonant with the spin-singlet transition.
- Characterization of magnetic field sensitivity at room temperature.
Main Results:
- Demonstrated significant light absorption from NV centers in diamond at room temperature using an optical cavity.
- Achieved a measured magnetic field sensitivity of 2.5 nT/√Hz.
- Projected photon shot-noise-limited sensitivity of 70 pT/√Hz and quantum projection-noise-limited sensitivity of 250 fT/√Hz for a specific sensing volume.
Conclusions:
- Cavity enhancement enables efficient room-temperature operation of NV-diamond magnetic field sensors.
- The developed sensor shows potential for high-sensitivity magnetic field measurements with projected sensitivities reaching the fT/√Hz range.
- This work paves the way for practical, compact, and sensitive magnetic field sensing technologies.
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