Acceleration and deceleration of quantum dynamics and shortcuts to adiabaticity based on inter-trajectory travel with fast-forward scaling theory*

Quantum information processing requires fast manipulations of quantum systems to overcome dissipative effects. In this talk, we show a method to accelerate quantum dynamics to obtain a desired target state in a shorter time compared to unmodified dynamics. We apply the theory to a system consisting of two linearly coupled qubits. Our method enables one to derive control parameters which realize target end states of adiabatic dynamics in shorter periods of time, thus realizing a shortcut to adiabaticity. Furthermore, we address experimental limitations to the rate of change of control parameters for quantum devices which often limit one’s ability to generate a desired target state with high fidelity. Naively scaling down the rate of change of control parameters will in general not produce the desired target state, leading to a loss of fidelity. We show that an initial state following decelerated dynamics can reach a target state while varying control parameters more slowly, enabling more experimentally feasible driving schemes.