Mark E. Limes

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Twinleaf Work Princeton Work Utah Work

Twinleaf Work

I am currently working for Twinleaf LLC mostly on a DARPA AMBIIENT grant, Atomic Magnetometer for Biological Imaging In Earth's Native Terrian (say that five times fast). Some popular articles about this project are at Daily Mail and DARPA. Our technique uses fast laser pulsing to optically pump Rb in Earth's field (0.5 G) with a goal of achieving 1 fT_{rms}/cm\sqrt{Hz} (currently at 10 fT_{rms}/cm\sqrt{Hz} in Phase 1). Our gradiometer uses a baseline of 3 cm, and aims to be dead-zone and heading error free, for the purpose of in-the field magnetoencephalography (fancy speak for readin' 1-100 Hz brain waves).

Also doing a bunch of varied magnetometry projects for Twinleaf, and helping develop a GNOME (Global Network of Optical Magnetometers for Exotic physics)) setups based around a self-compensating comagnetometer.

Here is my talk that I presented for DAMOP 2020.

Princeton Work

In the Romalis group, I worked on a free-precession, dual noble-gas comagnetometer that is detected with an alkali magnetometer. This device shows potential for use as a chip-scale reference NMR gyroscope (studied in collaboration with Twinleaf LLC), as well as searches for exotic spin couplings. Our device has reached a precision sufficient to constrain spin-gravity searches at the 10 nHz level, and is accurate enough for detection of Earth's rotation without calibration. This work is supported by DARPA and NSF grants.
NSF grant #1404325

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A continuation of this work is being supported by an ONR grant, where 3He-21Ne cells are used. Initial testing shows that our 3He-21Ne cells are working well, with a 21Ne relaxation of roughly 2 hours.

3He21Ne129Xe Oh My!

Utah Work

In the Saam group, I worked on hyperpolarizing noble gases with alkali metals, and did basic research in magnetic resonance under an NSF grant and a Swigart Foundation grant. In addition, I collaborated with the Boehme, Lupton, Raikh, and Vardeny groups at University of Utah, using magnetic resonance techniques to characterize organic semiconducting material under an NSF MRSEC grant.

NSF grant #1121252
NSF grant #0855482