Reverse quantum annealing of the p-spin model with relaxation

In reverse quantum annealing, the initial state is an eigenstate of the final problem Hamiltonian and the transverse field is cycled rather than strictly decreased as in standard (forward) quantum annealing. We present a numerical study of the reverse quantum annealing protocol applied to the $p$ -spin model ( $p=3$ ), including pausing, in an open-system setting accounting for dephasing in the energy eigenbasis, which results in thermal relaxation. We consider both independent and collective dephasing and demonstrate that in both cases the open-system dynamics substantially enhances the performance of reverse annealing. Namely, including dephasing overcomes the failure of purely closed-system reverse annealing to converge to the ground state of the $p$ -spin model. We demonstrate that pausing further improves the success probability. The collective dephasing model leads to somewhat better performance than independent dephasing. The protocol we consider corresponds closely to the one implemented in the current generation of commercial quantum annealers, and our results help to explain why recent experiments demonstrated enhanced success probabilities under reverse annealing and pausing.In reverse quantum annealing, the initial state is an eigenstate of the final problem Hamiltonian and the transverse field is cycled rather than strictly decreased as in standard (forward) quantum annealing. We present a numerical study of the reverse quantum annealing protocol applied to the $p$-spin model ($p=3$), including pausing, in an open-system setting accounting for dephasing in the energy eigenbasis, which results in thermal relaxation. We consider both independent and collective dephasing and demonstrate that in both cases the open-system dynamics substantially enhances the performance of reverse annealing. Namely, including dephasing overcomes the failure of purely closed-system reverse annealing to converge to the ground state of the $p$-spin model. We demonstrate that pausing further improves the success probability. The collective dephasing model leads to somewhat better performance than independent dephasing. The protocol we consider corresponds closely to the one implemented in the current generation of commercial quantum annealers, and our results help to explain why recent experiments demonstrated enhanced success probabilities under reverse annealing and pausing.

arXiv:1911.07186Physical Review AFeb 25, 202056 citations

Optimal quantum annealing in p-spin model

Kostyantyn Kechedzhi, Vadim Smelyanskiy

Bulletin of the American Physical SocietyMar 4, 20150 citations

Dynamics of reverse annealing for the fully connected p -spin model

Yu Yamashiro, Masaki Ohkuwa, Hidetoshi Nishimori +1 more

Reverse annealing, a variant of quantum annealing, is investigated by probing quantum transitions in a $p$ -spin model and comparing it with the predictions offered by equilibrium statistical mechanics. It is shown that reverse annealing can provide an exponential speedup over conventional quantum annealing for this particular problem.Reverse annealing, a variant of quantum annealing, is investigated by probing quantum transitions in a $p$-spin model and comparing it with the predictions offered by equilibrium statistical mechanics. It is shown that reverse annealing can provide an exponential speedup over conventional quantum annealing for this particular problem.

arXiv:1906.10889Physical Review ANov 18, 201976 citations

Quantum annealing of disordered spin systems

Lukas M. Sieberer, Philipp Hauke, Ehud Altman +1 more

Bulletin of the American Physical SocietyMar 13, 20170 citations

p

-spin model (

p=3

), including pausing, in an open-system setting accounting for dephasing in the energy eigenbasis, which results in thermal relaxation. We consider both independent and collective dephasing and demonstrate that in both cases the open-system dynamics substantially enhances the performance of reverse annealing. Namely, including dephasing overcomes the failure of purely closed-system reverse annealing to converge to the ground state of the

p

-spin model. We demonstrate that pausing further improves the success probability. The collective dephasing model leads to somewhat better performance than independent dephasing. The protocol we consider corresponds closely to the one implemented in the current generation of commercial quantum annealers, and our results help to explain why recent experiments demonstrated enhanced success probabilities under reverse annealing and pausing.

Reverse annealing, a variant of quantum annealing, is investigated by probing quantum transitions in a

p

-spin model and comparing it with the predictions offered by equilibrium statistical mechanics. It is shown that reverse annealing can provide an exponential speedup over conventional quantum annealing for this particular problem.