AQC 2016 - Coupled Quantum Fluctuations and Quantum Annealing

A Google TechTalk, June 29, 2016, presented by Layla Hormozi (MIT) ABSTRACT: We study the relative effectiveness of stoquastic and non-stoquastic Hamiltonians consisting of coupled quantum fluctuations compared to Hamiltonians with single spin flips in the performance of quantum annealing. We focus on problem Hamiltonians resembling the Sherrington-Kirkpatrick model of Ising spin glass and examine the performance of different types of driver Hamiltonians with coupled fluctuations by numerically calculating the success probabilities and minimum gaps in systems of up to 20 spins. We find that both stoquastic and non-stoquastic Hamiltonians with coupled fluctuations can provide improvement over Hamiltonians with single spin flips. However, the effectiveness of each driver Hamiltonian and the relation between success probability and the properties of minimum gaps suggest different mechanisms behind their performance. Presented at the Adiabatic Quantum Computing Conference, June 26-29, 2016, at Google's Los Angeles office.