Adaptive measurement approach towards controlling non-adiabatic transitions in quantum annealing

Non-adiabatic transitions arising from extremely small energy gaps present a challenge to quantum annealing and adiabatic quantum computing. In realistic quantum annealing scenarios, one does not have a priori knowledge of the energy-spectrum and hence the location of minimum energy gaps; thereby making it difficult to design strategies that will slow down close to the points of enhanced transition probability out of the ground state. In this work, we present an adaptive annealing protocol based on measurement of the energy-level curvature. Numerical results are presented for a random transverse field Ising model. We also discuss the relationship between the measurement operator and the fidelity-susceptibility, a measure allowing analysis of quantum phase transitions in many-body systems.

This material is based upon work supported by the Intelligence Advanced Research Projects Activity (IARPA) and the Army Research Office (ARO) under Contract No. W911NF-17-C-0050. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Intelligence Advanced Research Projects Activity (IARPA) and the Army Research Office (ARO).