BSAC Technology Seminar: Hyperpolarized Quantum Sensors

September 28, 2021

Professor Ashok Ajoy

Department of Chemistry, UC Berkeley

“Quantum sensor” technologies have opened attractive new applications stemming from the ir sensitive detection of magnetic fields. This is typified by the Nitrogen Vacancy (NV) center in diamond that has allowed the nanoscale sensing of spins in materials, molecules, and biological systems through optical means. In this talk, Professor Ashok Ajoy will describe a complementary modality of how such quantum sensors could assist in the injection of spin polarization into surrounding nuclei, “hyperpolarizing” them into athermal spin states that are far from equilibrium and allowing their magnetic resonance signatures to be enhanced by several orders of magnitude[1-2].

Professor Ajoy will show that this portends the ability to construct new sensor platforms from hyperpolarized nuclear spins, exploiting their remarkable spin coherence properties at room temperature[3]. This yields interesting new applications for gyroscopes, underwater and high-field magnetometers, and ultimately, “deployable” magnetic resonance sensors that can allow chemically specific analyte and metabolite tracking.

[1] A. Ajoy, et al , Sci. Adv. 4, 5 (2018).

[2] X. Lv, et al, PNAS 118, 21 (2021)

[3] W. Beatrez, et al, Phys. Rev. Lett. (in press) (2021)

BIO 

Prof. Ashok Ajoy received his B.E./M.S. from BITS-Pilani, India in 2010 and his Ph.D. under Prof. Paola Cappellaro at MIT in 2016. His graduate research, which MIT recognized with the Manson Benedict award (2014) and the Del Favero thesis prize (2017),  focused on nanoscale MRI using quantum sensors, with applications to NMR chemical probes at high resolution.

In 2017, Ashok joined Prof. Alexander Pines’ group in the Department of Chemistry at UC Berkeley as a postdoctoral researcher where he worked on new methods for laser-assisted spin hyperpolarization for signal enhancement in NMR. 

He is now an assistant professor in the UC Berkeley Department of Chemistry. His research group is currently investigating: 

  • NMR Quantum Microscopy
  • Quantum Assisted Hyperpolarization
  • Quantum Sensing and Computing
  • Nanoscale Spin Dynamics

His recent work on magnetic resonance imaging in diamond particles has received lots of attention with the 2021 publication of  “Background-free dual-mode optical and 13C magnetic resonance imaging in diamond particles” in PNAS.

In this work, his group combined magnetic resonance imaging with optical imaging in diamond microparticles, which enabled them to remove background signals and generate clear images. Their approach relies on the nitrogen vacancy (NV) center-driven optical nuclear hyperpolarizability in diamond particles, that renders them “bright” in MRI while simultaneously fluorescing optically.


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Watch this BSAC Technology Seminar

Hyperpolarized Quantum Sensors

September 28, 2021
BSAC Technology Seminar Series
Professor Ashok Ajoy, UC Berkeley
Hosted by Berkeley Sensor & Actuator Center
bsac.berkeley.edu

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BSAC Technology Seminar Committee

Kamyar Behrouzi
Clark Nguyen
Mutasem Odeh
Dalene Schwartz Corey
Alp Sipahigil (Chair)
Anju Toor