A variational eigenvalue solver on a photonic quantum processor

Quantum computers promise to efficiently solve important problems that are intractable on a conventional computer. For quantum systems, where the physical dimension grows exponentially, finding the eigenvalues of certain operators is one such intractable problem and remains a fundamental challenge. The quantum phase estimation algorithm efficiently finds the eigenvalue of a given eigenvector but requires fully coherent evolution. Here we present an alternative approach that greatly reduces the requirements for coherent evolution and combine this method with a new approach to state preparation based on ansätze and classical optimization. We implement the algorithm by combining a highly reconfigurable photonic…

• NS
  National Science Foundation

  Awards: DE-FG02-97ER25308, 0955518, CHE-1037992, PHY-0955518, 1037992
• UD
  U.S. Department of Energy

  Awards: FG02-97ER25308, DE-FG02-97ER25308, DE-FG02-, DE-FG02
• AP
  Alfred P. Sloan Foundation
• JT
  John Templeton Foundation
• CA
  Camille and Henry Dreyfus Foundation
• RA
  Royal Academy of Engineering
• NN
  National Natural Science Foundation of China

  Awards: 61033001, 61361136003
• EA
  Engineering and Physical Sciences Research Council

  Awards: EP/L024020/1, EP/J017175/1, EP/K021931/1
• NK
  National Key Research and Development Program of China

  Awards: 61033001, 2011CBA00301, 61361136003, 2011CBA00300
• DO
  Division of Chemistry

  Award: CHE-1037992
• AF
  Air Force Office of Scientific Research

  Awards: FA9550-, FA9550-12-1-0046, FA9550, FA9550-12, FA9550-12-1