Alumni Interview with Riccardo Comin

Now a full-time assistant professor at MIT, Riccardo Comin is an alumnus of the Stewart Blusson Quantum Matter Institute (SBQMI) who continues to engage with networks across disciplines and institutions. In January, he joined SBQMI's Lukas Chrostowski in a career panel hosted at UBC and through the Condensed Matter seminar series, presented on his group's most recent findings on the nanoscale charge and spin fabric in quantum solids.

When curiosity and quantum interests collide
For some, curiosity drives their learning choices rather than the desire for a qualification.

Riccardo Comin's interest in quantum materials research began while he was writing his high school thesis in his hometown of Udine, Italy. He used examples from quantum mechanics to point out modern challenges to the positivist view, a worldview in which true knowledge of the natural world rests on what we can see and observe. However, during the early 20th century, this viewpoint was challenged by the work of Werner Heisenberg and other pioneers in quantum mechanics who were studying phenomena that could not be observed or quantified with absolute precision. 

This early interest in quantum mechanics would eventually draw Riccardo to study strongly-interacting quantum electronic solids and pursue a successful academic career as an assistant professor of physics at MIT.

How did you come to study physics at UBC?
"I came to UBC in 2009, right after graduating from my alma mater, Universita’ degli Studi di Trieste, in Italy. At that time, my career decisions were solely driven by curiosity. With my former research group, I was working on some interesting problems in classical physics (the liquid-glass transition) but I had also heard about this new class of interesting problems in the field of quantum materials and I was intrigued by that. I knew [UBC] was one of the best places to study [this] kind of [science]."

Since his undergraduate advisor in Italy happened to be Andrea Damascelli's former professor a few years back, he helped arrange a meeting between the two in Italy, at a bar near the Milan railway station where a dodgy wifi set-up allowed them to view photos and data on their early ARPES experiments. After a two-hour conversation, Comin knew that he wanted to study these fascinating materials, where quantum effects not only matter at the atomic scale but also underlie complex macroscale phenomena such as superconductivity.

Angle-resolved photoemission spectroscopy or ARPES is the name of a technique used to study the electronic energy levels of valence electrons in crystalline solids. The technique provides information about an electron's kinetic energy and momentum, or velocity, all of which can be studied by freeing electrons from a material’s surface. These electronic energy levels are also referred to as "quasiparticle excitations."

Curiousity as a driver of new techniques and research approaches
Thanks to a UBC 4-year graduate fellowship, Comin was able to pursue PhD studies at the Stewart Blusson Quantum Matter Institute (formerly the Quantum Matter Institute) at UBC. It was a life decision involving a range of challenges, from learning a new language and adapting to a different environment to the difficulty of maintaining connections with family and friends back home. However, he has no regrets about making the move.

"The environment here is unique. You sometimes hear about the world’s ranking of universities in broad categories such as science or physics but if one were to do a specific ranking of best places for quantum materials, UBC would no doubt be among the top 5 on the global scene."

Comin was present in the early 2010s when the idea for a Canadian institute dedicated to the study of quantum materials research was first proposed.

"Theories of the quantum many body problem are very complex," explains Comin. “To uncover the exotic properties of quantum solids, it is essential for theorists and experimentalists to work together.”

The many-body problem encompasses the phenomenology of systems of many particles (e.g., electrons) with strong interactions between them. While the quantum problem can be solved analytically for simple systems such as the hydrogen atom, special methods are needed to tackle interacting, many-electrons systems such as those you find in macroscopic systems, from quantum solids to neutron stars.

Cross-pollination between theory and experiments has always been engraved in the core philosophy of QMI thanks to the leadership of scientists like George Sawatzky – one of the few people in the world who can embrace both aspects.

Under Sawatzky's tenure, UBC researchers in electrical computer engineering, chemistry and physics began pooling their knowledge and resources to order to extend their capacity for quantum materials research. The Stewart Blusson Quantum Matter Institute evolved organically out of their discussions, collaborations and shared sense of curiosity.

"[It's because] the more you find out, the more you want to [discover]. And to know more, you need more techniques. You need higher energy resolution, higher levels of brightness, lower temperatures. You need new facilities, new probes, new approaches. And then come new ideas and expanded knowledge."

SBQMI's organizational and research model grew out of these needs and the institute has since expanded its range of lab, technical and human resources under the direction of Andrea Damascelli. In 2015, the institute received an award of $66.5 million from the Canada First Research Excellence Fund (CFREF) in order to fund a national program for research in quantum materials and future technologies.

How did your experience at SBQMI lead to your current position and research interests?
"The opportunities that I could pursue at [SBQMI] were foundational for my decision to specialize as a group leader at MIT in the field of quantum materials.

"[The institute] creates an interdisciplinary and highly collaborative environment that is coherently focused on an intriguing set of problems. It’s a privilege to work in such a special context, where we are given the opportunity to apply our passion for science and follow our intellectual curiosity. It's the kind of place where you fall in love with quantum materials, that's what QMI is, and UBC is one of the world leading environments for its research."

Building a career by complementing PhD studies with postdoctoral work
After graduating UBC in 2014, Comin began postdoctoral work in the Sargent group at the University of Toronto, where he studied emerging new materials for optoelectronic applications and where he learned new skills in material synthesis (the building of new materials from the ground up) and characterization, as well as device fabrication.

How did your doctoral studies at SBQMI complement postdoctoral work?
"At QMI, I focused on spectroscopic studies of quantum materials, but I had never contemplated the opportunities for application of these or other systems to achieve some novel functionalities. I chose to work with the Sargent group because I wanted to explore the applied side of materials research. It was a unique learning experience that greatly helped me grow as a scientist and expand my expertise."

The questions Comin now explores revolve around the behavior of complex quantum matter at the nanoscale, where these materials are all but homogeneous. These ensembles of particles form new collective states manifesting an inner beauty and properties that cannot be inferred from the characteristics of their fundamental constituents. Comin believes that the new scientific frontier in this field will be in the application of known techniques onto ever-smaller materials and devices, one of the grand challenges of modern condensed matter physics.

"To examine a quantum electronic state of matter and to try to understand its emergent properties from what we know about the single electron is like taking a snapshot of a [human] cell and projecting from there what a whole individual will look like. It’s basically impossible to use mere inference from the laws of physics in these situations. We can only adapt our paradigms and establish higher principles to encompass the complexity of the many-body world."

However, dealing with hierarchies of complexity not only leads to a problem of description but it also generates new intriguing phenomena.

"What I found intriguing is the idea of a realm of possibilities that are there, waiting to be explored. I thought the research [addressed] a complex problem but at the same time was rich with promising new physics to be discovered and contemplated."

Story: Sophia Han with Riccardo Comin
Photography: Paul Joseph, UBC Brand and Marketing and Pinder Dosanjh