Southwest Quantum Information and Technology

Long range multibody coupling of flux qubits that preserves the gap in quantum annealing

Presenting Author: Evgeny Mozgunov, University of Southern California
Contributing Author(s): Antonio Martinez, Edward Tang, Adrian Lupascu, Vicky Choi

Quantum annealing was proven to be an effective optimization algorithm in all-to-all connected systems. Unfortunately, realistic devices so far have been limited to 2-body spatially local 2d lattice of interactions. A promising approach to overcome these limitations is to realize couplers as paramagnetic trees: locally-interacting trees of ancillae obeying a transverse-field Ising model with the gap large compared to qubit energy. We present the conditions under which the minimal gap of the non-local multibody system Hamiltonian along the quantum annealing schedule is unchanged if the couplings are implemented as paramagnetic trees. The caveats in this approach are that the circuit model of the tree nodes in practice will be operated outside the limit where the effective qubit description is accurate, and the noise is amplified by the tree.

(Session 5 : Sunday from 5:00pm - 7:00pm)