Adiabatic speedup via zero-energy-change control in a spin system
Licheng Zhang, Feng-Hua Ren, Yifei Chen, Run-Hong He, Yongjian Gu, Zhao-Ming Wang · Europhysics Letters (EPL) · 2019
Adiabatic evolution is required in performing quantum information processing tasks and adiabatic speedup is often used to avoid decoherence problems for a long evolution time.Here, we add a leakage elimination operator (LEO) Hamiltonian to the evolution and adiabatic speedup can be obtained.LEO Hamiltonians can be realized by a sequence of periodic zero-energy-change pulses.By using the Feshbach P -Q partitioning technique, we obtain the exact control parameters to realize adiabatic speedup for different types of pulses.Furthermore, we show that this control scheme is fault-tolerant against pulse strength and pulse frequency for specified thresholds.