The implementation of many-body interactions is relevant in various areas of quantum information. We present a superconducting device that implements a strong and tunable three-body interaction between superconducting quantum bits, with vanishing two-body interactions and robustness against noise and circuit parameter variations. These properties are confirmed by calculations based on the Born-Oppenheimer approximation, a two-level model for the coupling circuit, and numerical diagonalization. This circuit behaves as an ideal computational basis ZZZ coupler in a simulated three-qubit quantum annealing experiment. This work will be relevant for advanced quantum annealing protocols and future developments of high-order many-body interactions in quantum computers and simulators.
@article{arxiv.1909.02091,
title = {Tunable three-body coupler for superconducting flux qubits},
author = {Denis Melanson and Antonio J. Martinez and Salil Bedkihal and Adrian Lupascu},
journal= {arXiv preprint arXiv:1909.02091},
year = {2019}
}