MRL MVPs: Smitha Vishveshwara

Nobel laureate Anthony Leggett is her grandfather: her academic grandfather, that is. (He was her PhD advisor’s PhD advisor.) Her biological family, however, is no less impressive. Her father was a renowned physicist who studied black holes, and her mother is a prominent molecular biophysicist. You could say that physics is in her DNA.  

But physics isn’t the only thing in Smitha Vishveshwara’s blood; so are the arts. Her grandfather was a playwright, and her uncle was a violinist. By combining an unconventional upbringing in India with formal training in quantum physics, Vishveshwara has seamlessly woven science and art together.  

“It was wonderful,” Vishveshwara says. “I did everything a physics major did and was also in a college scholars program where there weren’t any requirements, so I had the flexibility to be focused or very broad. Along with physics, I took up creative writing, literature, African dance, music, you name it. And it was a blast.” 

Vishveshwara went on to the University of California, Santa Barbara for her graduate studies. She says, “As the plane dipped down over Santa Barbara, I looked at the ocean and I thought, ‘Thank goodness the physics is great here!’ It was my first immersion with the ocean, and I just fell in love with it. It’s still very much a part of me and I’m drawn to it.” 

After graduate school, Vishveshwara had what she describes as a “scary time” during which she had to navigate towards the next stage of her career. She had support from her PhD advisor, Matthew Fisher, and other mentors, but was at a crossroads: on top of the typical uncertainties of new graduates, she was anxious to continue pursuing her passion for writing and other creative outlets. She embarked on a national tour of postdoctoral interviews. She found that the opportunity at Illinois resonated strongly with her. “It’s because of the people,” Vishveshwara says. “And because of the curiosity with which they approached science. It’s their quest to ask something deeper.”

During Vishveshwara’s postdoc at Illinois, her advisors were Anthony Leggett and Paul Goldbart. “I have had so many mentors here, my wonderful postdoc advisors included,” she says. “I have ended up collaborating with so many of my colleagues, from senior theorists to experimentalists to junior researchers, and I’ve learned so much from each one of them.” 

In 2005, Vishveshwara was offered a tenure-track faculty position in the Department of Physics at Illinois. She is also an affiliate of the Materials Research Laboratory (MRL), the Beckman Institute for Advanced Science and Technology, and the newly renamed Anthony J. Leggett Institute for Condensed Matter Theory and a researcher in the Illinois Quantum Information Science and Technology Center (IQUIST). 

Quantum Creatures

As a “pen and paper” theorist, Vishveshwara enjoys thinking about the what ifs and letting her imagination flow. “The language of math is a beautiful way of discovering new things, but the physicality of it also matters. I love proposing things that can be realized in experiments and also studying the mysteries that experiments bring. It’s been an amazing playground here at Illinois for that,” she says.   

Vishveshwara studies quantum condensed matter theory, which explores the behavior of complex systems of atoms and molecules. She explains, “I get to study the strongly correlated behavior of quantum communities, so to speak. The question is, when these individuals come together as a collection and have interactions, what is the emergent behavior? Then we add quantum physics to the mix, which I get more and more enamored and mystified by the deeper I go; then there’s all these fascinating phases of matter.” 

In lower dimensions, the correlations are more important. For example, if you are swimming in three dimensions, the chances of encountering another swimmer are much lower than they would be if you were swimming in a two-dimensional plane.  

One of the first explorations Vishveshwara embarked on was looking at interactions in two dimensions. “In quantum physics, there are different kinds of quantum particles, like electrons, neutrons, protons. These are ‘unfriendly’ particles,” she explains. “Bosons are ‘friendly’ kinds of particles, and a lot of the phenomena that you see around you—everything from the behavior of metal, semiconductors, superconductors—you have to understand these quantum ‘creatures’ to understand why they behave the way that they do. And not only things on Earth, but even neutron stars and black holes. It turns out that in two dimensions, there are these strange quantum creatures called ‘anyons.’ And I was fascinated by that.” 

Vishveshwara also studies ‘shells’ of superfluids, which are like balloons made of superfluid rather than rubber. They are challenging to realize in the laboratory because they are destroyed by Earth’s gravity. She had studied their behavior, but only as a theoretical concept.  

According to Vishveshwara, this is an exciting time for her research because anyons have long been predicted but not detected. After about 40 years of research efforts, two experimental groups finally saw the first evidence of anyons during the last few months.  

As for the superfluid shells, at the height of the COVID-19 pandemic, an experimentalist contacted her and one of her collaborators to discuss the possibility of realizing them in microgravity conditions aboard the International Space Station. “It was so meaningful because we could have sat around despairing about the virus, but we said ‘let’ study it!’ It was powerful, because a virus that kept us apart actually brought us together to put our shared investigations to use,” she says.  

You can't kick a black hole

When Vishveshwara and her sister were growing up in India, their parents took turns walking them to the bus stop. During these walks, Vishveshwara and her father would talk about everything from the mundane to the cosmic. One day, she asked him what he did for a living, and he answered, “I show that you can’t kick a black hole.” His work had shown that black holes were stable, and that perturbations wouldn’t disrupt them. When a black hole is jolted, it gives off what is called a ‘ringdown,’ much as a bell settles after it has been struck. What comes out of a black hole’s ringdown is a gravitational wave, which was predicted by Einstein more than 100 years ago but not observed until 2016.  

Many years after that conversation, Vishveshwara sat her father down and said that it was time he taught her for real about Einstein’s theory of relativity. “And he made me a deal,” she says. “He said, you’ve gone and learned this thing called quantum physics, so you teach me quantum and I’ll teach you relativity. So, we started teaching each other, and we said, why not make this into a popular physics book?” 

Written in the form of letters between the father and daughter, Two Revolutions: Einstein’s Relativity and Quantum Physics leads the scientifically curious reader through two remarkable branches of physics that dramatically changed both authors’ perception of nature. From the subatomic to the astronomical realms, the pair wove a tapestry of scientific insight, history, personal anecdotes, philosophy and wonder.  

Unfortunately, Vishu passed away in 2017 before the publication of their book, but Vishveshwara found solace in completing the work they had begun. Endorsed by Tony Leggett; Rohini Godbole, an Indian scientist Vishveshwara has known since childhood; George Ellis, a South African physicist; and Richard Blanco, President Barack Obama’s inaugural poet, Two Revolutions is set for a December 2024 release.  

International Year of Quantum

Beyond the publication of her book, Vishveshwara has an exciting year ahead. The United Nations has declared 2025 to be the International Year of Quantum Science and Technology (IYQ). According to a June 7, 2024 proclamation, the yearlong, worldwide initiative will “be observed through activities at all levels aimed at increasing public awareness of the importance of quantum science and applications.”   

As a member of the IYQ steering committee, Vishveshwara will play a significant role in shaping the initiative. “It’s been amazing to see the whole thing play out,” she says. “Quantum is unifying. There’s this notion of community and harmony. If you go to the fundamentals of who we are, the story of light, where we come from, and the universe itself from its very seed and to all that you see around you, and you take quantum from that perspective, even looking to MRI, this lifesaving thing, then you see that there’s a sort of unity and coming together. And to me, that’s beautiful.”