RAISE: TAQS: Fast multiqubit control of high-coherence transmons for efficient quantum chemistry simulations

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

Quantum chemistry is one of the most promising near-term applications of modest-sized quantum computers. Quantum computers are devices that exploit the principles of quantum mechanics for computation. The goal is to solve problems that are intractable using even the most powerful supercomputers available. This research project aims to advance the simulation of molecules using quantum computers. The research team is developing methods to encode large molecules on relatively small and highly specialized quantum devices. These devices are made from state-of-the-art superconducting circuits operated with high-precision control schemes. A transdisciplinary approach that combines expertise in Physics, Chemistry, Engineering, and Materials Science is being taken to simulate molecules of increasing complexity over the course of the four-year project. The ability to perform such simulations could have a transformative effect on scientific, technological, and medicine applications, such as materials and drug design. Aspects of the proposed research also directly impact quantum computing, which has well-known repercussions for national security. Furthermore, this project contributes to the interdisciplinary education of the next generation of researchers in quantum information science. The research team also engages in outreach efforts which include mentoring high school students and establishing activities aimed at attracting Chemistry students into the field of Quantum Information Science. Modest-sized quantum computers are expected to surpass the capabilities of classical devices in solving quantum chemistry problems with high simulation accuracy. This project aims to solve quantum chemistry problems in quantum devices by developing an approach in which the orbitals are encoded in a smaller number of highly optimized qubits, using state-of-the-art superconducting circuits controlled with fast, high-fidelity quantum gates. The multi-disciplinary research team designs, implements, and optimizes platforms of highly connected transmons tailored to simulate strongly correlated molecules. Key elements of this research are: (i) Novel mappings between molecules and quantum processors that leverage effective Hamiltonians and additional levels in the transmons (qudits); (ii) Highly efficient state preparation protocols implemented with ultrafast two-qubit entangling gates and multi-qubit gates beyond the standard toolbox; (iii) High-coherence devices based on Josephson junctions, with device connectivity guided by the effective Hamiltonians, state preparation protocols, and quantum gate designs. Molecules of increasing complexity are simulated through mutually informed advances in quantum chemistry algorithms, devices, materials, and quantum control. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.