Ultrafast coherent excitation of a 40Ca+ ion

Abstract

Fast entangling quantum gates can significantly enhance the performance of a trapped-ion quantum computer. In pursuit of implementing a fast two-qubit gate, we investigate the coherent excitation of a ^40 Ca ^+ ion with a train of picosecond pulses resonant to the 4S _1/2 $\leftrightarrow $ 4P _3/2 transition. The optical pulse train is derived from a mode-locked, stabilized optical frequency comb. We implement two techniques to characterize the pulse-ion interaction and show how all requirements can be met for an implementation of a fast phase gate operation.

Keywords

• quantum computation
• ultrafast phase gate
• ultrafast laser
• ultrashort pulses