Towards a high fidelity Rydberg interaction gate

Sammanfattning: Trapped Rydberg ions with their extraordinary properties serve as very good candidatesfor quantum computing and quantum simulation. The strong dipole-dipoleinteraction in Rydberg ions enables fast entangling gates between qubits. The entanglementdoes not involve motional quantum state to exchange information, whichmakes it suitable to perform gate operations in a long ion string. In this report,preliminary studies for cooling the trapped ions using polarization gradient coolingand addressing of single ion in a long ion string have been done. The results showthat for cooling of multiple ions in a linear chain, a combination of Doppler coolingand polarization gradient cooling provides better cooling as compared to Dopplercooling alone. Simulations for single ion addressing shows that the focusing of thebeams on the ions can be further improved by using additional optics described bythe simulation. Better focusing is essential to deliver higher laser intensities to theion such that the Rabi frequency is higher. This is important for improving the delity of gate operation in long ion strings.