There's strong evidence that some problems in quantum chemistry and physics may never be solved. That's not holding back an Indiana University physicist from calculating the impossible.
Phil Richerme is an associate professor of physics in the College of Arts and Sciences at IU Bloomington. Recently, he was named to the third cohort of the Gordon and Betty Moore Foundation's Experimental Physics Investigators.
The Gordon and Betty Moore Foundation strives to advance scientific discovery and address important issues at a scale that makes measurable impacts. Its Experimental Physics Investigator Initiative was established to support the next generation of scientific leaders opening new frontiers in the field by funding imaginative research that explores uncharted areas. Launched in 2022, the initiative plans to support 120 mid-career scientists over six annual cohorts.
"This initiative is designed to support novel and potentially high-payoff projects that will advance the field of physics but might be hard to fund through traditional funding sources," said Theodore Hodapp, program director for the initiative. "Via an open call for proposals, we have lowered the barriers for researchers from a wide range of institutions and experiences to apply. We are delighted with the variety of ideas and projects this year's cohort represents."
IU Bloomington's Department of Physics faculty consistently rank among the best in their respective fields. The department's research interests cover a wide range of subfields, such as astrophysics, atomic physics, quantum information, neutrino physics and more.
"Professor Richerme is a groundbreaking scholar at the forefront of applied quantum science and technology, an exciting new field of research that will spur innovation and develop tools that will drive further discoveries in physics, chemistry and engineering, among other fields," said Rick Van Kooten, executive dean of the College of Arts and Sciences and a professor of physics.
Richerme is one of 19 physicists named to the cohort and the first IU faculty member. The award's accompanying $1.25 million will allow Richerme to continue to conduct boundary-pushing research.
"There's this risk of getting locked into a research program without really testing some riskier but more impactful research," Richerme said. "The Moore Foundation allows you to push the envelope and do something unique that has the potential to be transformative."
At the intersection of quantum physics and quantum chemistry, Richerme's research focuses on problems that classical computers can't solve. These problems require solving the Schrödinger equation, a differential equation that governs how wave functions change over time. Classical machines, such as computers or even supercomputers, are not equipped to solve the equation for more than a handful of particles at a time.
Marissa D'Onofrio graduated from Richerme's lab in 2022. She is now a postdoctoral researcher at Duke University's quantum center. Photo by Anna Powell TeeterRicherme's lab will develop a state-of-the-art quantum computer that is custom-tailored to perform complex computations, like Schrödinger's. Then, his lab can identify processes that happen inside of quantum chemical processes at the molecular level.
According to Richerme, it doesn't take much power for quantum computers to do something that typical ones cannot. For example, 32 quantum bits - the individual particles for information storage and processing - can encode around 32 gigabytes worth of random-access memory. With 300 quantum bits, you can encode as many classical bits of information as there are the number of particles in the universe.
"If we could figure out how to use a quantum computer to do this, this really is a paradigm shift in the way that people do quantum chemistry," Richerme said. "It's not trial and error anymore.
"You propose a molecule, and you calculate what its effects are going to be. Then you know if it's going to be successful or not before investing billions of dollars in processes, or trying to look through possibilities to see what might work and what won't."
An optics table in Richerme's lab shows an ion trap and the lasers used to control it. Photo courtesy of Phil RichermeIf successful, Richerme would provide the first known path toward calculating chemical dynamics processes, or the rate and mechanisms of chemical reactions, using quantum hardware. This could revolutionize computational chemistry by making it possible to solve currently unsolvable problems. Such computing can address complex chemical problems that are crucial for processes like CO2 reduction, artificial photosynthesis and nitrogen fixation.
Richerme said this work was born out of previous collaboration with three IU colleagues: Department of Chemistry professors in the College of Arts and Sciences Srinivasan Iyengar and Jeremy Smith, and Luddy School of Informatics, Computing and Engineering computer science professor Amr Sabry.
For several years, the group was funded by a National Science Foundation program that bring experts from different disciplines together to evaluate different perspectives on quantum chemical problems.
"Honestly, it took us probably about a year or two coming from different backgrounds just to figure out how to talk to each other and to develop a shared language," Richerme said. "Now that we have, there's been an explosion in productivity and the amount of scientific progress we've been able to make."
