In this episode of The New Quantum Era, host Sebastian Hassinger comes to you again from Rensselaer Polytechnic Institute, during their launch event in April 2024 for the deployment of an IBM System One quantum computer on their campus. RPI invited me to lead a panel discussion with members of their faculty and IT team, and provided a podcast studio for my use for the remainder of the week, where he recorded a series of interviews. In this episode Sebastian interviews Di Fang, an assistant professor of mathematics at Duke University and member of the Duke Quantum Center. They discuss Dr. Fang's research on the theoretical aspects of quantum computing and quantum simulation, the potential for quantum computers to demonstrate quantum advantage over classical computers, and the need to balance theory with practical applications. Key topics and takeaways from the conversation include:

- Dr. Fang's background as a mathematician and how taking a quantum computing class taught by Umesh Vazirani at UC Berkeley sparked her interest in the field of quantum information science
- The potential for quantum computers to directly simulate quantum systems like molecules, going beyond the approximations required by classical computation
- The importance of both proving theoretical bounds on quantum algorithms and working towards practical resource estimation and hardware implementation to demonstrate real quantum advantage
- The stages of development needed to go from purely theoretical quantum advantage to solving useful real-world problems, and the role of Google's quantum XPRIZE competition in motivating practical applications
- The long-term potential for quantum computing to have a disruptive impact like AI, but the risk of a "quantum winter" if practical results don't materialize, and the need for continued fundamental research by academics alongside industry efforts

In this episode of The New Quantum Era, we're diving deep into the intersection of quantum computing and chemistry with Jamie Garcia, Technical Program Director for Algorithms and Scientific Partnerships Group with IBM Quantum. Jamie brings a unique perspective, having transitioned from a background in chemistry to the forefront of quantum computing. At the heart of our discussion is the deployment of the IBM Quantum computer at RPI, marking a significant milestone as the first of its kind on a university campus. Jamie shares insights into the challenges and breakthroughs in using quantum computing to push the boundaries of computational chemistry, highlighting the potential to revolutionize how we approach complex chemical reactions and materials science.

Throughout the interview, Jamie discusses the evolution of quantum computing from a theoretical novelty to a practical tool in scientific research, particularly in chemistry. We explore the limitations of classical computational methods in chemistry, such as the reliance on approximations, and how quantum computing offers the promise of more accurate and efficient simulations. Jamie also delves into the concept of "utility" in quantum computing, illustrating how IBM's quantum computers are beginning to perform tasks that challenge classical computing capabilities. The conversation further touches on the significance of quantum computing in education and research, the integration of quantum systems with high-performance computing (HPC) centers, and the future of quantum computing in addressing complex problems in chemistry and beyond.

Jamie's homepage at IBM Research
How Quantum Computing Could Remake Chemistry, an article by Jamie Garcia in Scientific American

Sebastian interviews Professor Lin Lin during the System One ribbon cutting event at Rensselaer Polytechnic Institute in Troy, NY. Professor Lin Lin's journey from computational mathematics to quantum chemistry has been driven by his fascination with modeling nature through computation. As a student at Peking University, he was intrigued by the concept of first principles modeling, which aims to simulate chemical systems using minimal information such as atomic species and positions. Lin Lin pursued this interest during his PhD at Princeton University, working with mathematicians and chemists to develop better algorithms for density functional theory (DFT). DFT reformulates the high-dimensional quantum chemistry problem into a more tractable three-dimensional one, albeit with approximations. While DFT works well for about 95% of cases, it struggles with large systems and the remaining "strongly correlated" 5%. Lin Lin and his collaborators radically reformulated DFT to enable calculations on much larger systems, leading to his faculty position at UC Berkeley in 2014.

In 2018, a watershed year marked by his tenure, Lin Lin decided to tackle the challenging 5% of strongly correlated quantum chemistry problems. Two emerging approaches showed promise: artificial intelligence (AI) and quantum computing. Both AI and quantum computing are well-suited for handling high-dimensional problems, albeit in fundamentally different ways. Lin Lin aimed to leverage both approaches, collaborating on the development of deep molecular dynamics using AI to efficiently parameterize interatomic potentials. On the quantum computing side, his group worked to reformulate quantum chemistry for quantum computers. Despite the challenges posed by the COVID-19 pandemic, Lin Lin and his collaborators have made significant strides in combining AI and quantum computing to push the boundaries of computational chemistry simulations, bridging the fields of mathematics, chemistry, AI, and quantum computing in an exciting new frontier.

Thanks again to Professor Lin and everyone at RPI for hosting me and providing such an amazing opportunity to interview so many brilliant researchers.