While completing his bachelor’s degree at Hobart and William Smith Colleges in nearby Geneva, New York, Matthew Church, PhD student in Chemistry and Chemical Biology, confesses that he fell in love with the Finger Lakes region. “Aside from the prestige of the university, Cornell’s scenic location, the proximity to wine country, and Ithaca’s personality drove me to apply here.”
Church also had a compelling academic reason for applying to Cornell. He came to the university, hoping to work in the Ananth Group, a theoretical chemistry lab led by Nandini Ananth, Chemistry and Chemical Biology. After a couple of months on campus and upon consulting with graduate students who were working in the lab, Church applied for a research position and became a member of the group in November 2014.
Church is a true theorist. “I really like the lifestyle of a theorist. Experimental work is good, but being a theorist is much more challenging.” He studies methods for chemical simulations, which will eventually be useful in designing products such as chemical sensors and renewable materials.
Describing and Analyzing Molecular Chemical Reactions, Accurately
Church’s research involves analyzing complex chemical processes on a molecular level. He seeks to better understand the nature of chemical systems’ quantum effects, which are effects that traditional physics models such as Newton’s Laws are unable to explain. Therefore, quantum mechanics is required to explain these effects, and Church has been working on optimizing a newer method that can accurately compute the characteristics of such quantum effects.
Nuclei are surrounded by electrons which exert a force, and this force consequently determines nuclear motion. Different electronic configurations around the nuclei will result in different kinds of nuclear motion. The Ananth Group studies physical processes and chemical reactions where nuclei can undergo a change in their electronic configuration. This is referred to as nonadiabatic dynamics, and quantum-based methods are required to describe it.
“We’re particularly interested in the effects that overlapping states have on atoms and molecules," Church says. "An accurate theoretical treatment of such problems is currently needed. Existing methods generally fail because they do not consider factors such as the high-dimensionality of quantum mechanics and the need of a quantum mechanical phase to include interference effects.”
Nandini Ananth formulated mixed quantum-classical initial value representation (MQC-IVR)—a method for analyzing quantum effects—along with Sergey Antipov, a postdoctorate working with her in 2015. Now, Church is working on improving its efficiency. Church characterizes the method as semiclassical. It combines elements of classical physics and quantum mechanics.
“Our method allows us a substantial degree of control over analyzing chemical processes. Therefore, we can use MQC-IVR to push semiclassics where it is most needed—in complex chemical systems.”
“Semiclassical methods aren’t new to the field,” Church says, “but the ability to apply them to large chemical systems has been absent until recently.” The mixed quantum-classical method, Church asserts, has the right solutions to these problems. “Our method allows us a substantial degree of control over analyzing chemical processes. Therefore, we can use MQC-IVR to push semiclassics where it is most needed—in complex chemical systems.”
According to Church, the mixed quantum-classical method practiced in the Ananth lab is the most viable option for studying certain quantum effects, owing to its accuracy. "Semiclassical methods have only been applied to low dimensional systems in the past, because in complex systems, there have been too many oscillations to integrate over. But the method we have developed makes the integration much easier.”
The Right Place and Bona Fide Aspirations
Although he initially struggled with some aspects of the research process, Church found his colleagues incredibly supportive and collaborative. “I’m absolutely certain that, while I have worked hard during my tenure at Cornell, I would be 100 steps back if it weren’t for the people around me.”
Interacting with his colleagues and professors, Church says, is his favorite aspect of the research experience. “The collaborative environment here does not generally exist in most graduate schools, and I am very grateful for having found it here.”
Upon acquiring his PhD degree, Church plans to remain in the academic world, probably as a professor, and he’s well on the way. He received the 2015/2016 Bayer Teaching Excellence Award for his performance as a teaching assistant. In the 2016/2017 school year, he earned the Howard Neal Wachter Memorial Prize for being one of two top graduate students in physical chemistry.
“Teaching has been a long-term fascination for me, and I would ideally like to teach at a liberal arts school. I still have a couple of years to think, though, so I haven’t made a definitive call yet.”