A Scientist's Quest to Photograph the Atom and Life at Large

Beginning with a perfect analogy for cutting open an atom, Vandana Sharma, takes us through the crests and troughs of her research on atom probing machines.

Vandana with one of the RIM systems she has built. Credit: The Life of Science

Vandana with one of the RIM systems she has built. Credit: The Life of Science

“Say you have two fruits: an apple and a mango. To see which one has the bigger seed, you have to first cut it, right? Here the fruit is an atom.”

“The knife to cut an atom is made of charged particles or a source of light. With this, we can cut the atom and observe the fragments coming out and see how they evolve over a period. We can trace back the history of the atom. And now with the advent of laser technology, we can image this in real time!”

With this analogy, Vandana Sharma introduced me to her field of research. The 37-year-old heads the ‘Few Body Quantum Dynamics Laboratory’ at IIT Hyderabad, one of the eight new IITs founded in 2008.

Being less than ten years old with a brand new campus, the institute was not initially on my lab-hopping list. However, the university website changed my mind. It appeared that the R&D wheels were rolling already. Besides, I noticed a happy predominance of young faculty members, many of whom have returned home after being trained at prestigious institutions abroad. Sharma is one of them.

How to cut open an atom

When she first adopted the research problem of imaging atoms during her Ph.D, it was already known that if a charged particle or a photon (a tiny particle of light or electromagnetic radiation) was made to bombard an atom or a molecule sample, this collision would result in the usually-neutral atom losing an electron and becoming positively charged or ‘ionised’. Instruments equipped with specialised detectors can sense, amplify and record the electrons that are generated from this collision. These signals tell scientists more about the construction of this atom or the molecule sample it came from.

Though the technology was there, the instruments, called Recoil Ion Momentum Spectrometers (RIMS), were unavailable in India. Even for prestigious academic research institutions like the ISRO-funded Physical Research Laboratory (PRL) in Ahmedabad, where Sharma did her Ph.D, or even IIT, they were too expensive. That’s why back in the early 2000s Bhas Bapat, her Ph.D guide, thought it would be a good idea for them to build their own. This had never been done before in India.

It was a tall task. Bapat was one of the newer faculty members at PRL at the time and Vandana was his only student. “There was nothing in our lab, whereas the other students who joined (for Ph.D) in the same batch had everything in theirs,” recalled Vandana. It was a frustrating period for her.

The parts they required – such as the detector and the laser – needed to be ordered and each order took six months to arrive. Some other parts had to be designed from scratch in the lab and the design sent to companies who would fabricate it accordingly. Further time was spent on tweaks and defects to be corrected. “All this took about three-four years, and it was a struggle to watch my batchmates already doing experiments and starting to write papers. I thought I will not be able to finish my Ph.D.”

But fortunately for Sharma, the toughest part was over. “After that, it took only two-three months for me to do the experiments and acquire all the data. My batchmates had already submitted their papers but I was the first to get my paper accepted – the last to submit, but the first to get published,” she smiled widely. Sharma went on to publish seven papers during her PhD.

Vandana and the machine

Today, almost ten years after its creation, the detector has come a long way. It has been used successfully to probe into simple molecules like oxygen, carbon dioxide and carbon tetrachloride. Soon, it will be ready for experiments with more complex molecules, even DNA. The key is the inbuilt detector that amplifies any signal detected.

If an oxygen molecule is the sample, it is first ionised and then when the O2 ion hits the surface of the detector, two secondary electrons are released. This goes on to release four more electrons, followed by eight and then 16, so much that eventually an ‘electron cloud’ is formed which can be recorded by the machine Sharma helped built with her guide.

The electron cloud itself tells us very little but the data about where the ion hit and what time it hit gives Sharma specifics on the structure of the sample molecule. “We can tell how the electrons are arranged in the atom – if the electron came from a low energy level (close to the nucleus of the atom) or a high energy level (close to the outer surface of the atom).”

But don’t we already know about the electronic configuration of atoms? I asked, recalling high school physics. Sharma replied, “For many things we do – for atoms it’s very well studied, but for molecules it’s not. We are only starting out with O2 – we know a lot about it so we can compare our results and see if our system works fine. Now that we know it does, we can go ahead to bigger molecules like DNA, bacteria…”

The system she has developed cannot be patented as the technology is not new, however the resolution obtained is leaps ahead, so Sharma believes that hers has an edge.

Determined to be a ‘Dr.’

Growing up in Khetri Nagar, Rajasthan, Sharma dreamt of becoming a medical doctor. But remembering biological facts was never her strength, she said. Vandana could not secure an MBBS seat. She took up B.Sc in Physics at Rajasthan University. By then, however, she’d gotten attached to the idea of having ‘Dr.’ prefixed to her name, and when she realised that there was still a way, she was set for an M.Sc and a Ph.D.

Unfortunately, her father had decided that she would go for a Master’s in Computer Application(MCA). “Being from a village he used to think computer science was the only growing science.” When she resisted, her father warned that he would not fill up any of her (M.Sc.) forms and that he would fix her marriage. “That was a very strong slap on my face. I did not want to get married.” But both father and daughter were stubborn and for a whole week, Sharma was given the silent treatment.

Meanwhile, Sharma heard the results for the IIT entrance exam were out. She listened disbelievingly as the recorded message on her phone informed her that she was ranked 17! Vandana told her sister about this but it seemed too incredible to announce it to her father just yet. She wasn’t sure what his reaction would be. Before she had the chance to tell him, the postman rang the bell. “It’s a small town you know. He told my father some counselling letter has come, sweet chahiye (I want celebratory sweets).” Her father was puzzled at first but when she told him it must be her IIT results, he opened the letter to check. “Then he said ‘Vandana, prepare your bags, you have to go to IIT.’”

During her M.Sc at IIT Roorkee Sharma got the exposure in physics she needed badly. “Back in the village, I only had a few good teachers. I did not even know what a Ph.D was, though I knew that with a Ph.D you will get the ‘Dr.’ title. In Roorkee, I really could understand what physics is. I cleared all the exams and got into PRL for my Ph.D.”

Sharma let me in on a happy accident in her life that she says she’s never talked about before. “In the first few months of Ph.D coursework, I went to my (future) Ph.D boss for the first time. It was actually not to join his research group but just to talk to him about how long a Ph.D will take and whether I will be able to get a postdoc after that. I was not very fluent in English. So maybe because of this, he understood from what I said that I am joining him and he congratulated me and welcomed me to his group. I was shocked – what did I say! And so, because of a play of words – either I said it wrong, or he got it wrong – this happened.”

After her Ph.D, Sharma did postdocs in the US and in Germany. The former was especially meaningful to her. “The reason my father was fixated on an MCA degree was because he wanted me to go to the US, come back and open a school. At the gate of the school, he said, there should be a sign: Hindi is not allowed here.” She explained that this desire of his came from his struggles with English. “His goal was to open an affordable English school in our hometown. I told him I don’t know if I can fulfil your dream but I will try to go to US for sure. When I did, he was very happy.”

Kinds of discrimination

Sharma is married and has a child with her fellow-physicist husband. They were both working in Europe, she in academics and he in the industry, when they decided to come back to India after battling the infamous ‘two-body problem’ in academia (where a couple in academia find it difficult to obtain jobs in the same university. It’s likely that in such cases, the female gives up her professional life for the sake of the family staying together). Sharma beats the odds. Today, her husband works at Tata Institute of Fundamental Research, Hyderabad. “I would say that he compromised a little bit but still we are both happy because we are in the same city. I feel both should be in the same place because productivity increases.”

Sharma went through another trial while applying for jobs when she was pregnant in Germany. “If they see you are pregnant – even if they say no discrimination on paper, it’s not true. This happens everywhere, not just in India. I was shortlisted for many positions but in the final step I lost out because I was pregnant,” she said.

After she delivered her baby, she noticed things got a bit easier, but while sitting for interviews for faculty positions in India, she realised there was a new type of discrimination facing her. “The kind of questions they ask… They asked me ‘your husband is in the Netherlands and you are applying here, how will you manage?’ I felt like giving it back to them! Why don’t they realise that if I have applied for the position, I must have thought about this? Why should they worry? The interviewers must not worry about my family matters – I will take care of that. They don’t ask this from any male applicants. This is really a drawback for women.”

Now, seated on the other end of the table, Sharma is careful to be straightforward about her hiring policy. “If I find a female candidate better than a male candidate, I will prefer the better candidate. If the candidate drops out, it is a loss for the system (that has trained them). To disqualify the female based on an assumption that she will drop-out along the way is unfair. A male also can make that decision, right? A candidate may have many offers, and a female has as much right as a male to choose the best one for her.”

Working at a new IIT where buildings are still coming up and a lot of infrastructure is still under construction is a challenge, admitted Sharma, but it gives her a lot of freedom that she cherishes. “You become a pillar of this institute, you feel proud. You may not get as much time as you want for research, but you are making path for the newcomers.” Now that the instruments she’s developed are complete, fully tested, and the experiments have begun, Vandana’s lab is on the brink of an interesting future.

This piece was originally published by The Life of Science. The Wire is happy to support this project by Aashima Dogra and Nandita Jayaraj, who are travelling across India to meet unsung women scientists.

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