Dr. Avisek Chatterjee is a postdoctoral researcher at the University of Toronto, working under the supervision of Nobel laureate Prof. John Polanyi. He has a PhD in Chemistry from University of Waterloo and a BSc and MSc in Chemistry from Visva-Bharati University in India.
Tell me a little bit about your research.
The focus of our research group has been to study the dynamics of chemical reactions by various methods; currently we are using mostly Scanning Tunneling Microscopy (STM) to study the reactions of single molecules. I concentrate on investigating reaction dynamics of single organic molecules on metal (copper) surfaces at liquid helium temperatures (~ −268 °C). The goal of operating at such low temperatures is to freeze all the other modes of energy (thermal) available to the molecule and to concentrate only on excitation energies supplied to the molecule by the STM tip.
What exactly is Scanning Tunneling Microscopy (STM)?
STM makes use of the concept of quantum tunneling. Quantum tunneling is the phenomenon that occurs when a particle moves beyond a classically forbidden energy state – think of it as rolling a ball up a hill. Similarly, when the conducting tip (which has an atomically sharp apex; ideally with one single atom at its end) of the microscope is brought close up to a surface, a voltage difference between the two creates an electron transfer in the vacuum formed between them. This is called a tunneling current. The conducting tip scans across the surface of your sample, and the dynamics of this tunneling current gives you information about the surface, creating the microscopic image.
How did you get interested in this area of research?
I was studying STM of organic molecules on silicon surfaces for my PhD and so I was familiar with Prof. Polanyi’s recent research. I have always loved chemical reaction kinetics and mechanisms since my undergrad days, and I was immediately hooked. After my PhD at Waterloo, I was pretty fortunate to get an opportunity to work with this high-profile research group.
What is a typical day like for you?
To me every day is different. We do different things like organizing various experiments, discussions, and writing scientific papers. We have sub-groups within our research group that focus on different projects going on simultaneously using a variety of instruments and techniques. We also have theoreticians who help us understand our experimental results. For our sub-group, once the experiments start, they usually run for 24 hours for at least two weeks. So in a typical day, if I am conducting experiments, I am in the basement of Lash Miller Chemical labs. Otherwise, I am doing analysis of our experimental results or discussing them with our theoreticians and also with Prof. Polanyi.
What are your favourite aspects of your daily routine/research? What are your least favourite aspects?
I like everything I do in the lab: conducting experiments, discussing results and meetings with Prof. Polanyi. If I have to pick any particular aspect, I would say that the meetings with Prof. Polanyi are quite interesting and delightful. He has an amazing personality; his vast knowledge in chemistry, economics, politics and so many other fields makes him an ideal person to have conversation with.
What are some challenges you see in your own field (academically, economically, culturally, or in terms of bureaucracy) personally and as part of a research community? How do you think they are best addressed?
I came to know that in Canada the future of fundamental science is not very promising. The Canadian government is continuously cutting budgets and making it increasingly difficult for the researchers to procure funds. Focusing only on industry-oriented research won’t help the frontier of science to move forward and without advancement in fundamental science, technology will not move forward either.
What would be your advice be to those interested in pursuing your field of research? What do you still not know that you wish you did? Is there a particular technique or discovery that would greatly accelerate research in your field, something we can’t do today?
These days, scientific instruments are becoming increasingly more complex with the addition so many different technologies. To thrive in the world of Scanning Tunneling Microscopy, one needs a sound understanding of chemistry, physics, electronics and vacuum techniques. To those who want to pursue a career in nanoscience and technology, I would suggest acquiring a good knowledge base in the aforementioned areas. I wish I knew more electronics!
Scanning Tunneling Microscopy helps to obtain images of single atoms or molecules! This is the lowest resolution one can achieve today and has unprecedented advantages when compared to electron microscopes. The only problem is that this technique does not give us chemical information about a given molecule – all we can see is its electron density. If we are able to integrate other chemical specific techniques, such as infrared spectroscopy, X-ray photoelectron spectroscopy, etc. with STM, it would become an unparalleled technique for studying and manipulating individual molecules and atoms.
What are your interests outside of research? How do you de-stress and how does it compliment your work?
I like to play sports like soccer, cricket and squash regularly. Soccer is my favourite sport and I believe that without playing soccer I wouldn’t be able to function normally in daily life. It keeps me motivated and focused, and helps me to have clear perspective on things.