Skip to content

MQI

Seminar

A variational eigenvalue solver on a quantum processor

McClean, J (Harvard University)
Thursday 28 November 2013, 10:00-11:00

Seminar Room 1, Newton Institute

Abstract

Co-authors: Alberto Peruzzo (University of Sydney), Peter Shadbolt (University of Bristol), Man-Hong Yung (Tsinghua University), Xiao-Qi Zhou (University of Bristol), Peter Love (Haverford College), Alan Aspuru-Guzik (Harvard University), Jeremy O'Brien (University of Bristol)

Quantum computers promise to efficiently solve important problems that are intractable on a conventional computer. For quantum systems, where the dimension of the problem space grows exponentially, finding the eigenvalues of certain operators is one such intractable problem and remains a fundamental challenge. The quantum phase estimation algorithm can efficiently find the eigenvalue of a given eigenvector but requires fully coherent evolution. We present an alternative approach that greatly reduces the requirements for coherent evolution and we combine this method with a new approach to state preparation based on ans\"atze and classical optimization. We have implemented the algorithm by combining a small-scale photonic quantum processor with a conventional computer. We experimentally demonstrate the feasibility of this approach with an example from quantum chemistry: calculating the ground state molecular energy for He-H+, to within chemical accuracy. The proposed appro ach, by drastically reducing the coherence time requirements, enhances the potential of the quantum resources available today and in the near future.

Video

The video for this talk should appear here if JavaScript is enabled.
If it doesn't, something may have gone wrong with our embedded player.
We'll get it fixed as soon as possible.

Back to top ∧