Locality in Quantum Computations

Aspuru-Guzik Group, Harvard

A hydrocarbon is shown along with a small piece of the quantum circuit used to determine its energy. The number of operations needed to run this circuit can be large. By considering how the magnitude of interactions decreases with distance (shown through a red to white gradient in the image), many operations can be neglected (boxes that have been crossed out) without a significant loss of accuracy. 

Below are four draft images, as well as the final image used on the cover of The Journal of Physical Chemistry Letters. 

The paper:
McClean Jarrod R., Babbush Ryan, Love Peter J., and Alán Aspuru-Guzik  Exploiting Locality in Quantum Computation for Quantum Chemistry The Journal of Physical Chemistry Letters, 2014, 5, 4368-4380.