Continuous-time quantum control across an exponentially small bottleneck in a frustrated Ising ring model
Researchers used continuous-time quantum control to optimize annealing schedules for a frustrated Ising ring model with an exponentially small spectral gap bottleneck. By employing a 'dressed-CRAB' approach, they found that population transfer away from the ground state and back later allows the system to bypass this bottleneck. This results in ground-state preparation times growing linearly with system size instead of exponentially.