The 38th Robert S. Mulliken Lecture: Molecular Electronic Structure at the Nexus of Classical and Quantum Computing

While significant progress has been made in classical quantum chemistry methods since Robert Mulliken's time, modeling molecular processes involving highly entangled electronic states remains a grand computational challenge. Quantum computers offer a promising solution, with their ability to efficiently represent and manipulate exponentially complex entangled quantum states using a linear number of qubits. In this talk, I will discuss several ways quantum computation may be integrated with classical quantum chemistry methods to enable the modeling of strongly entangled states. I will introduce quantum unitary downfolding approaches and illustrate how they help leverage existing quantum hardware to perform accurate quantum computations with significantly smaller quantum measurement costs. I will also discuss the projective quantum eigensolver, a novel quantum algorithm for trial-state optimization on near-term noisy quantum computers that is a competitive alternative to variational quantum algorithms. These new techniques in combination with more accurate quantum hardware with hundreds of qubits will help establish a systematic path to predictive simulations of chemical reactions, excited state dynamics, and complex catalytic processes.