Ashok Ajoy (photo John Fyson)
We are really delighted to welcome Assistant Professor of Chemistry Ashok Ajoy to the College of Chemistry. Ashok most recently held a postdoctoral appointment in the lab of Alex Pines, the Glenn T. Seaborg Professor Emeritus at UC Berkeley’s College of Chemistry. During his postdoctoral research, he headed up an international team of scientists from the Department of Energy’s Lawrence Berkeley National Laboratory and UC Berkeley who discovered a way to exploit defects in nanoscale and microscale diamonds to strongly enhance the sensitivity of magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) systems while eliminating the need for their costly and bulky superconducting magnets.
Photo from left: Emanuel Druga, Ashok Ajoy, Dieter Suter, Kristina Liu, and Raffi Nazaryan were part of an international team led by Alex Pines that discovered how to exploit defects in powdered diamonds in a way that could strongly enhance the sensitivity of MRI and NMR machines. (Courtesy: Berkeley Lab)
Ashok said of the study, “This has been a longstanding unsolved problem in our field, and we were able to find a way to overcome it and to show that the solution is very simple.”
Ashok received his Ph.D. from MIT in nuclear science and engineering with advisor Paola Cappellaro. His thesis was entitled: “Quantum assisted sensing, simulation, and control”.
Ashok joined the Department of Chemistry as an assistant professor in July. We caught up with him recently in his lab.
What type of research do you do?
In general, I work in the interface between NMR spectroscopy and quantum science. It's interesting because there are many forms of spectroscopy; each has its special features. What we study with magnetic resonance are actually nuclear spins. All matter is made of atoms and at the center of the atoms are nuclei. Several of these nuclei, just by their nature, are endowed with a quantum mechanical object called “spin”. This spin is a very highly coherent, which means that you can make a clock out of the nuclear spin. If you set it precesssing in a magnetic field, it can precess about a billion times before losing its coherence.
It's like nature's little clock given to you for free. And these clocks, as you set them precessing, can report on their local chemical environment. Nuclei don't participate in chemical reactions, they report on the electrons that are around them. They are forming chemical bonds, and chemical structure. Today’s advances in quantum science is allowing us the ability to manipulate these quantum objects, and through them discern chemical structure better than ever before.
This is exciting because it brings together two disparate fields. Quantum technology and chemistry are usually considered orthogonal to each other. For the first time, scientists are researching at the interface between these two areas .
Where did you grow up?
I grew up in Bangalore, a city in the South of India. It's one of India's largest tech hubs. I did my schooling there. It's a very nice place. It's got great weather, just like California.
What’s your favorite childhood memory?
I have many fond memories. We used to have a lot of kids in the neighborhood. However, what really got me interested in science was my family, in particular my dad. My dad is a very creative engineer. He's a builder. He almost built our entire house. One day he built a desk for me to study at just because I didn't have one. As I moved through my career and eventually landed in the United States, I realized that because there are fewer resources in India, you have to learn to be creative.
I still have not matched my father’s level of creativity, but that's what got me interested and made me curious about how one could make things ... use things around us to do something cool.
What kind of engineer is your father?
He is an electrical engineer. He used to make radios. But generally engineering across the board.
You have attended universities on three continents. You went to school in India, Germany, and the United States. What's your favorite continent?
That's a very good question actually. I think each place has its own strengths, but I should say the United States is special. The first day I landed at MIT, I joined a new group. I was one of the group’s early graduate students. And it so happened that as the group grew, there were no American students, including the PI. I think, this is testament to the welcoming nature of the United States. It's not important where you originally come from; what you look like; how you speak.
It's a true meritocracy. And I think that is a hard to find anywhere else. As long as you're talented and you have something to bring to bear you can really flourish. It's a special place.
What interested you in going to school in Germany?
Well, it was mostly fortuitous. I was looking for research opportunities and there were few in India at the time. I wrote to a professor in Germany and actually he didn't respond. This is the professor I finally landed up working for. And then my mentor in India wrote to him, and I got an opportunity to go there. It was my first real introduction to working in a larger research environment and at the interface of magnetic resonance and quantum science. The PI, Dieter Suter, has become a very close friend and we are still collaborating many years later. This was a great experience.
I was doing a little bit of NMR before that, but that was really the place where I learned NMR and quantum science together. Dieter is one of the pioneers in that field and he's also a very great mentor.
How many languages do you speak?
Indians speak a lot of languages. It's a very diverse place. I speak five languages. My mother tongue is a different language from the main one spoken in India. When I married my wife, I had to learn her language to speak with her parents.
India is like a little continent of many different peoples; who look different, speak differently and eat different things. Later I realized that when I moved, for instance to the United States, that we didn't have to think much about diversity in India because it was around us and ingrained in our system.
How does your international perspective as a scientist help you?
That's a really good question. First, I think it teaches you to respect diversity because I have lived in different places. If you construct a team, and all people are slightly different, for instance if they come from different backgrounds, or they have different training, that can really help you advance science and research.
I also think in a philosophical way, it tells us how special a University Berkeley is. Very few places have the kind of resources that are on offer here. Where I grew up, there were few laboratory resources. It's our responsibility, not only to be scholars, but also to promulgate our way of doing science so that we can encourage more people to join us.
What were your key research breakthroughs at MIT?
MIT is a cool place, very much a “doer” kind of place. My research at MIT focused on trying to push magnetic resonance, NMR and MRI to the nanoscale. People are familiar with MRI. You go into this big “tunnel” and you look at these images in your body in three dimensions, but what you're actually looking at are protons or hydrogen nuclei in the body. Humans are made up of 75% of water and that's the nuclei we are looking at. But it's still a macroscale image; the resolution in a current MRI or NMR experiment is a millimeter or so.
So it was an exciting time to be able to push NMR spectroscopy to the nanoscale; being able to actually view one molecule, or one cell nuclei which forms the basis for all matter. When you can see these nuclei, you can actually get all the information about the structure of the molecule, its dynamics and how the molecule folds. All of this power can be unlocked by NMR spectroscopy. As a community, we envisioned how NMR could be shrunken down, with light, to nanoscale and that’s what I worked on at MIT.
Microscopic images of diamond particles with nitrogen-vacancy defects. These samples, which exhibit a truncated octahedral shape, were used in experiments that sought new ways to tune and control an electronic property known as spin polarization. The scale bar at lower right is 200 microns (millionths of a meter). To the human eye, the pinkish diamonds resemble fine red sand. (Credit: Berkeley Lab)
When did you start researching with diamonds?
Diamonds are very special material for various reasons, but one imporant aspect is that it is a host to defects. It's actually the defects in diamonds that make them interesting. These defects can be used as nanoscale spin sensors. And that was a breakthrough in the 2000s by Jörg Wrachtrup and Fedor Jelezko in Germany. We were among the first groups to show how it could be used for nanoscale NMR spectroscopy.
And then when I moved to Berkeley, we realized that the first step of a quantum computer is to initialize the quantum spin, which means you want to align all spins in a particular direction. Aligning spins in a particular direction is also what a conventional NMR does through its large magnets.
People invest a lot of money to purchase very large magnets to align spins; and the alignment you get is a very small, a 10-100 part per million fraction. So using ideas from quantum computers, we can try and align spins more efficiently than you would in a magnet, using a laser.
Where do you think NMR and quantum research are headed?
I would say that it's an exciting time to be doing quantum research. A lot of people are focused on building quantum computers. They are interested in revolutionizing computing for special purposes like cryptography. There are a lot of interesting ideas about quantum simulations that are being pursued like simulating one quantum system with another. This has implications in superconductivity and simulating weather patterns.
I actually work in a third branch known as “quantum sensing”. NMR or magnetic resonance spectroscopy has been around for 60 years, but at its heart, what you're measuring are quantum objects. You're just not able to access the quantumness of these spins.. And now there is an exciting possibility where you can marry NMR research together with advances in quantum technology and bring it to bear on NMR spectroscopy.
With the advent of some of these new ideas in NMR, it may be possible to make NMR cheaper, faster, more portable, and also take it to different regimes that couldn't be accessible before. For instance, if you could do NMR at the single cell level, you might be able to unravel chemistry inside a cell. You can do NMR of a catalyst and look at catalysis at the nanoscale. NMR spectroscopy is very powerful, particularly because of its specificity.
It's a model free form of spectroscopy. You can read out from the spectrum, a fingerprint of the molecule without any prior knowledge about it. Usually it's very insensitive and you can't access the resolutions that are nanoscopic, but now with the advent of new ideas from quantum science it is actually possible to access these new regimes. This will be really exciting.
Switching tracks, what's your favorite color?
Maybe red. I don't actually have much of a preference.
What's your favorite sport and team?
A lot of Indians play cricket. It's not very popular in the US but it's quite an interesting game. I grew up playing it; it's a religion in India. I like the Australian cricket team; especially the team of five years ago. They were perhaps the best ever.
There's one form of cricket, which people play for five days called “test cricket” and people think it’s crazy. Why would you play a game for five days? But it turns out that there are subplots within the game and it really teaches you resilience. Sometimes when your team is down, you need one person to play for two days continuously without getting out. And that's where you need a lot of mental strength. As with all sports, it teaches you life lessons.
What is the first thing you're going to do when the quarantine is lifted?
I think we will just organize a large party for the lab. We have a large number of undergraduate students working in our lab. The lockdown has hit us hard because we have a skeletal number of people allowed in the laboratory at this time. We are experimentalists. We like to be in the lab. We are really looking forward to coming back.
Journal of Physics, Condensed Matter, "Processing quantum information in diamond"