Scalable Quantum Simulation of Molecular Energies
Venue
Physical Review X, vol. 6 (2016), pp. 031007
Publication Year
2016
Authors
Peter O'Malley, Ryan Babbush, Ian Kivlichan, Jonathan Romero, Jarrod McClean, Rami Barends, Julian Kelly, Pedram Roushan, Andrew Tranter, Nan Ding, Brooks Campbell, Yu Chen, Zijun Chen, Ben Chiaro, Andrew Dunsworth, Austin Fowler, Evan Jeffrey, Anthony Megrant, Josh Mutus, Charles Neil, Chris Quintana, Daniel Sank, Ted White, Jim Wenner, Amit Vainsencher, Peter Coveney, Peter Love, Hartmut Neven, Alán Aspuru-Guzik, John Martinis
BibTeX
Abstract
We report the first electronic structure calculation performed on a quantum
computer without exponentially costly precompilation. We use a programmable array
of superconducting qubits to compute the energy surface of molecular hydrogen using
two distinct quantum algorithms. First, we experimentally execute the unitary
coupled cluster method using the variational quantum eigensolver. Our efficient
implementation predicts the correct dissociation energy to within chemical accuracy
of the numerically exact result. Second, we experimentally demonstrate the
canonical quantum algorithm for chemistry, which consists of Trotterization and
quantum phase estimation. We compare the experimental performance of these
approaches to show clear evidence that the variational quantum eigensolver is
robust to certain errors. This error tolerance inspires hope that variational
quantum simulations of classically intractable molecules may be viable in the near
future.
