Determining spatial structures of ion crystals by simulated annealing method

Abstract

Calculating the spatial structures of ion crystals is important in ion-trapped quantum computation. Here we demonstrate that the simulated annealing method is a powerful tool to evaluate the structures of ion crystals. By calculating equilibrium positions of 10 ions under harmonic potential and those of 120 ions under anharmonic potential, both with the standard procedure and simulated annealing method, we find that the standard procedure to evaluate spatial structures is complicated and may be inefficient in some cases, and that the simulated annealing method is more favorable.

Research on the ions’ axial temperature of a sympathetically-cooled 113Cd+ ion crystal*

“…The sympathetic-cooling technology is effective for almost all particles, and significantly important in the precise measurement of particle spectrum and the study of particle properties. [7,8] Through sympathetic cooling technique, microwave clock based on sympathetically-cooled 113 Cd + ions [9] has been proven to be conducive to overcoming limits, including Dick effect and second-order Doppler frequency shift (SODFS), which result from the dead time of laser cooling process and rise in temperature during the clock interrogation, respectively. [10,11] Study has revealed that for the sympathetically-cooled ion crystal, trapped in the linear Paul trap, there exists a complex relationship between the electric parameters, including RF (radio frequency) voltage and end-cap voltage, and the temperature of ions.…”