%0 Journal Article %1 Peruzzo2013Variational %A Peruzzo, Alberto %A McClean, Jarrod %A Shadbolt, Peter %A Yung, Man-Hong %A Zhou, Xiao-Qi %A Love, Peter J. %A Aspuru-Guzik, Alán %A O'Brien, Jeremy L. %D 2013 %J Nature Communications %K quantumcomputing %R 10.1038/ncomms5213 %T A variational eigenvalue solver on a quantum processor %U http://dx.doi.org/10.1038/ncomms5213 %V 5 %X 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 ansätze 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 approach, by drastically reducing the coherence time requirements, enhances the potential of the quantum resources available today and in the near future.

@article{Peruzzo2013Variational, abstract = {{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 approach, by drastically reducing the coherence time requirements, enhances the potential of the quantum resources available today and in the near future.}}, added-at = {2019-02-23T22:09:48.000+0100}, archiveprefix = {arXiv}, author = {Peruzzo, Alberto and McClean, Jarrod and Shadbolt, Peter and Yung, Man-Hong and Zhou, Xiao-Qi and Love, Peter J. and Aspuru-Guzik, Al\'{a}n and O'Brien, Jeremy L.}, biburl = {https://www.bibsonomy.org/bibtex/295cb351588dacde1472c818d705dc6a5/cmcneile}, citeulike-article-id = {13299463}, citeulike-linkout-0 = {http://arxiv.org/abs/1304.3061}, citeulike-linkout-1 = {http://arxiv.org/pdf/1304.3061}, citeulike-linkout-2 = {http://dx.doi.org/10.1038/ncomms5213}, day = 10, doi = {10.1038/ncomms5213}, eprint = {1304.3061}, interhash = {7532c92d2883889771db33011f11b62a}, intrahash = {95cb351588dacde1472c818d705dc6a5}, issn = {2041-1723}, journal = {Nature Communications}, keywords = {quantumcomputing}, month = apr, posted-at = {2017-07-21 15:41:45}, priority = {2}, timestamp = {2019-02-23T22:15:27.000+0100}, title = {{A variational eigenvalue solver on a quantum processor}}, url = {http://dx.doi.org/10.1038/ncomms5213}, volume = 5, year = 2013 }