Carnegie Mellon University

Ashok Ajoy

Ashok Ajoy

Assistant Professor (as of June 2020), Chemistry

  • Mellon Institute

Education

2016-2019  Postdoctoral Associate, University of California Berkeley
2016  Ph.D. in Nuclear Science & Engineering, Massachusetts Institute of Technology
2010 M.Sc. in Physics and B.E. in Electrical Engineering, BITS Pilani

Research

Physical Chemistry, NMR, Quantum Science and Technology, Quantum Computation, Quantum Sensing, Machine Learning

We are a young experimental group focused on harnessing the power of quantum technologies in real-world chemical sciences. We develop new modalities of “quantum-enhanced” NMR and MRI to generate new analytical tools on-chip or on the benchtop, that marry together chemically-specific NMR spectroscopy, with the high spatial resolution, throughput, and ubiquity of a laser.

Our group thrives on interdisciplinary research at the intersection of chemical physics, engineering, and computation. Prof. Ajoy has strong links with the Electrical Engineering, Mechanical Engineering, and Physics departments on campus.

Projects

NMR Lab-on-a-chip and NMR Microscopy
NMR spectroscopy is a workhorse of chemical analysis, being noninvasive and allowing unique chemical fingerprints of different molecular constituents. However, NMR requires large unwieldy magnets and is expensive. Leveraging advances in “quantum sensing”, we are developing new chip-scale NMR detectors, and “NMR microscopes”, where NMR signals are obtained through light without requiring large magnets. This portends new advances in high throughput chemical screening and real-time analysis of chemical reactions in-situ.

Optical NMR hyperpolarization to “illuminate” materials and reactions
We are developing new quantum-assisted methods for “nuclear hyperpolarization”, a process of enhancing NMR signals just by “shining light” on samples. This is mediated by remarkable property of quantum sensors to be optically spin-polarized completely at room temperature and earth’s magnetic field. Such optical hyperpolarization would allow new classes of benchtop NMR instruments with high sensitivity, and would allow one to illuminate materials and chemical reactions with the simplicity of a laser and the chemical specificity of NMR.

Quantum computing and sensing
Our work builds on leveraging the fragility of quantum systems to deploy them as sensors in real-world chemical environments. The protocols and techniques we develop are directly relevant to quantum computing and quantum metrology. Inspired by quantum error correction, we develop quantum control methods for exploiting entanglement to push limits of spectroscopy towards single-molecule levels.

Machine Learning in Spectroscopy
We work on bringing to bear the power of machine learning (ML) and artificial intelligence to chemical spectroscopy. ML provides a new paradigm that directly can leverage the redundancy and over-constraints inherent to most chemical spectroscopy. The new class of NMR spectrometers that we develop lend themselves directly to ML techniques that at once can boast signal-to-noise and facilitate device miniaturization.

Publications

Orientation independent room-temperature optical 13C hyperpolarization in powdered diamond
A. Ajoy, K. Liu, R. Nazaryan, X. Lv, P. Zangara, B. Safvati, G. Wang, D. Arnold, G. Li, A. Lin, P. Raghavan, E. Druga, S. Dhomkar, D. Pagliero, J. Reimer, D. Suter, C. Meriles and A. Pines, Science Advances 4, eaar5492 (2018).

Enhanced dynamic nuclear polarization via swept microwave frequency combs
A. Ajoy, R. Nazaryan, K. Liu, X. Lv, B. Safvati, G. Wang, E. Druga, J. A. Reimer, D. Suter, C. Ramanathan, C. A. Meriles and A. Pines, Proc. Natl. Acad. Sci., 1807125115 (2018).

Hyperpolarized relaxometry based nuclear T1 noise spectroscopy in hybrid diamond quantum registers
A. Ajoy, B. Safvati, R. Nazaryan, J. T. Oon, B. Han, P. Raghavan, R. Nirodi, A. Aguilar, K. Liu, X. Cai, X. Lv, E. Druga, C. Ramanathan, J. A. Reimer, C. A. Meriles, D. Suter, and A. Pines, Nat. Comm.(in press) (2019). 

Dynamics of frequency-swept nuclear spin optical pumping in powdered diamond at low magnetic fields
P.R. Zangara, S. Dhomkar, A. Ajoy, K. Liu, R. Nazarian, D. Pagliero, D. Suter, J.A. Reimer, A. Pines, C.A. Meriles, Proc. Natl. Acad. Sci., 1811994116, (2019).

Selective decoupling and Hamiltonian engineering in dipolar spin networks
A. Ajoy, U. Bissbort*, D. Poletti and P. Cappellaro, Phys. Rev. Lett., 122, 013205 (2019).

Nanoscale vector DC magnetometry via ancilla assisted frequency up-conversion
Y. X. Liu, A. Ajoy and P. Cappellaro, Phys. Rev. Lett., 122, 100501 (2019).

Quantum Interpolation for High Resolution Sensing
A. Ajoy, Y.X. Liu, K. Saha, L. Marseglia, J.-C. Jaskula, U. Bissbort and P. Cappellaro, Proc. Natl. Acad. Sci. 114, 2149(2017).

Atomic-scale nuclear spin imaging using quantum-assisted sensors in diamond
A. Ajoy, U. Bissbort, M.D. Lukin, R.L. Walsworth and P. Cappellaro, Phys. Rev. X 5, 011001 (2015).  

Quantum simulation via filtered Hamiltonian engineering: application to perfect quantum transport in spin networks
A. Ajoy and P. Cappellaro, Phys. Rev. Lett. 110, 220503 (2013).

Stable three-axis nuclear-spin gyroscope in diamond
A. Ajoy and P. Cappellaro, Phys. Rev. A. 86, 062104 (2012).

Awards and Distinctions

Years Award
2017

Del Favero Thesis Prize, MIT

2014

Manson Benedict Award, MIT

2013

Co.Co.Mat Exchange Scholarship

2009

JNCASR Summer Research Fellowship

2008

Rajiv Gandhi Science Talent Research Fellowship

2007

IIA Summer Research Fellowship

2005

KVPY Scholarship, India

2003

National Talent Search Scholarship, India