Title: Quantum Computation for Quantum Chemistry

Speaker: Alan Aspuru-Guzik, UC Berkeley, Department of Chemistry

Date/Time: Monday, December 12, 2005, 10:00-11:00 am

Location: Building 980, Room 95 (Sandia NM)

Brief Abstract: The calculation time for the energy of atoms and molecules scales exponentially with system size on a classical computer, but polynomially using quantum algorithms. We demonstrate that such algorithms can be applied to problems of chemical interest using modest numbers of quantum bits. Calculations of the H2O and LiH molecular ground-state energies have been carried out on a quantum computer simulator using a recursive phase estimation algorithm. The recursive algorithm reduces the number of quantum bits required for the read-out register from approximately twenty to four. Mappings of the molecular wave function to the quantum bits are described. An adiabatic method for the preparation of a good approximate ground-state wave function is described and demonstrated for stretched H2. The number of quantum bits required scales linearly with the number of basis functions used and the number of gates required grows polynomially with the number of quantum bits.

CSRI POC: Alex Slepoy, (505) 284-3650