Physics Spotlight

July 2020
Physics Spotlight

Nikolay Prokof'ev

Moscow Engineering Physics Institute (1982), Ph.D., Kurchatov Institute (1987)

The Physics Department has chosen Professor Nikolay Prokof'ev to participate in this month’s Physics Spotlight! His research interests are strongly interacting systems of bosons, spins and fermions, as well as, the use and study of Monte Carlo Methods. As one of the Physics Departments Theoretical Condensed Matter Physicists, Professor Prokof'ev has taught several courses over the years, more recently PHY-614 Intermediate Quantum Mechanics I and PHY-615 Intermediate Quantum Mechanicals II in both the Spring and Fall semesters of 2019.

Prokof'ev is part of the Theoretical Quantum Fluids, Solids and Gases group here at the Amherst campus, regularly partnering with the Simons Foundation, and is also involved with our Precision Many Body Physics Group which began holding a conference once every two years starting in the Fall of 2018. The conference brings like-minded theorists and experimentalists who are interested in the development and application of controlled approaches to quantum matter. To find out more about Nikolay, his research and his path to Physics, please see his Q&A below!

What is your professional background?  What did you major in and where?  Where did you go to graduate school and for what?  How can your educational background help you teach and mentor students at UMass?

I graduated from the Moscow Engineering Physics Institute (MEPI). The Russian higher education system at the time was different from that of a typical US University. You had to declare your major before taking entrance exams, and these (both oral and written) exams were designed according to the major. After two years it was possible to further specialize in theoretical or experimental physics, and this is how I became a theorist. The curriculum was adjusted accordingly and heavily loaded with math and advanced physics courses. This definitely helped me with developing and teaching graduate level courses at UMass. To some degree the style is also influenced by my own educational experience---it is best to derive things rigorously and teach less instead of providing prescriptions and relying on intuition based on numerous “similar” examples. If something cannot be derived, it is time for research.   

Why did you decide to go to graduate school?  How did you decide which grad school to go to?  What advice would you have for a student who wants to go to graduate school?

Formally, there was no notion of a “graduate school” in Russia back then. The standard University education was rather specialized and at my school required five and a half years to complete (if I remember correctly, six days a week, no spring or fall breaks, and only two summer months). I would say that students graduated with an equivalent of at least a master’s degree. There was no need to take physics courses to continue towards a Ph.D., but we had to pass the qualifying exams. For me it meant that I was doing my Ph.D. at Kurchatov Institute in Moscow (an equivalent of the Los Alamos Laboratory in US) under Yuri Kagan. Yuri Kagan was lecturing Solid State Physics at MEPI, and I started working with him and Leonid Maximov when I was still a student. After graduation I simply continued my research work with them at their research institution. I cannot say that I knew what I was doing with my life when I decided to pursue research in theoretical condensed matter. The idea that I will spend the rest of my time sitting at the table was terrifying.

In 140 characters, explain your research:

Theoretical condensed matter physics with focus on strongly interacting systems of bosons, spins and fermions. If the problem can be addressed analytically, so be it; otherwise a numerical approach can work but only if the answer carries an error bar. 

What class in the undergraduate curriculum is closest to your research?

It is not just one class because math is as important as physics itself. The closest would be Math methods and Statistics, Quantum Mechanics, Solid State Physics, and Numerical Methods.

In General, what is your favorite class to teach, past or present?

It would be Monte Carlo Methods for graduate students. It originated from our research efforts, but the course is rather broad and interdisciplinary because the method itself is universal across all science disciplines. It is fun to teach how stochastic methods can be used to deal efficiently with a wide range of problems in classical and quantum statistics, kinetics, optimization, and quantum field theory.  

What do you like best about being a professor and a physicist at that?

Intellectual excitement of considering an interesting problem that defied solution for a very long time and trying to crack it. This is often painful and some projects are dropped after a lot of work, but it also happens that years later the proper way of addressing the problem is found. I have to say that one of the most rewarding things is when students start surprising you and teach me things that I can barely comprehend.

What is the most interesting research or project that you’ve worked on thus far?

Applying Monte Carlo methods to solve strongly interacting quantum field theories. As Nobel prize winner Steven Weinberg said (in Physics Today, 2011) “Also, it was easy to imagine any number of quantum field theories of strong interactions but what could anyone do with them?” I think that today (with the last paper still in preparation) we finally understand what to do about them (at least in the condensed matter setup).

What do you do outside of physics? Do you have a hobby?

I would like to answer this question with yes because I like hiking, skiing, swimming, gardening, woodworking, but the amount of free time is so limited that I often have to wait for months or years to engage in these activities.