Dissipative, Photon-Assisted Quantum Annealing

In accordance with dissipative, photon-assisted quantum annealing described herein, a collection of qubits model a Boolean optimization problem, and the solution is deter­mined by quantum annealing. However, rather than drive the qubits using a quasi-static field transverse to the computa­tional direction, spins are allowed to evolve between com­putational states by multi-photon, inelastic collective scat­tering into a common waveguide coupled transversely to all of the qubits. Transitions between arbitrary states are enabled by the continuum of modes of the waveguide, while avoiding the exponential sensitivity to low-frequency deco­herence near small gaps which is inherent in conventional QA. Moreover, because the transverse coupling to the wave­guide averages to zero, the spin of each qubit experiences a net field purely in the computational direction, allowing continuous, quantum non-demolition measurement of the system.