Prof. Kihwan Kim’s trapped-ion group at Center of Quantum Information of Institute for Interdisciplinary Information Sciences experimentally demonstrates the ideal shortcut to adibaticity for the first time. The paper, which is entitled as “Shortcuts to adiabaticity by counterdiabatic driving for trapped-ion displacement in phase space”, was published in Nature Communications on September 27th.

Figure 1：(a) Classical analogy of the counter-diabatic driving (HCD) to move the car to the desired direction (H0). (b) The STA protocol without any speed limit by including counter-diabatic driving.

Adiabatic dynamics plays an essential role in quantum technologies. Yet, environmentally-induced decoherence limits the implementation of adiabatic protocols. Recently, there has been an outburst of interest in finding short-cuts to adiabaticity (STA), that is, nonadiabatic driving schemes that mimic adiabatic evolution in arbitrarily short times. Among the wide variety of proposals and schemes to engineer STA, counter-diabatic driving stands out as the only driving protocol that induces a “fast-motion video” of the adiabatic trajectory of the system of interest as shown in Fig. 1. This is achieved by assisting the dynamics by an auxiliary counterdiabatic control field which suppresses the nonadiabatic excitations.

Figure 2：Experiment results. (a) The nonadiabatic excitation in the instantaneous basis of different shortcut methods. Only the counterdiabatic driving realizes the adiabatic following all the time. (b) Robustness tests. We assume the trap frequency drifts to a wrong value and measure the final excitation of different shortcuts designed with the original value. The result shows the counterdiabatic driving is the best result.

Here, we report the first experimental implementation of counterdiabatic driving for the adiabatic transport of a trapped ion in phase space and demonstrate its superior performance with respect to alternative schemes show in Fig. 2. Our experimental results clearly demonstrate that shortcut to adiabaticity protocols provide the shortest speed in the given resource, the most robust speedup against all the possible imperfections or noises in the system. The STA protocol based on the counter diabatic driving are broadly applicable in quantum technologies including the realization of quantum logic gates and adiabatic quantum computation, among others.

The experiments were carried out by IIIS PhD candidates Shuoming An and Dinghun Lv. Prof. Adolfo del Compo provided the theoretical supports. The research was funded by National Basic Research Program of China, the National Natural Science Foundation of China.

The full paper is available at：http://www.nature.com/articles/ncomms12999