Southwest Quantum Information and Technology

Doppler cooling of trapped ions under micromotion

Presenting Author: Alexander Kato, University of Washington
Contributing Author(s): Andrei Nomerotski, Boris Blinov

Extending ion traps into two dimensions is desirable to scale up the number of qubits for quantum computation and simulation. However, in radiofrequency (RF) traps, this can be difficult because of ion micromotion. Micromotion in trapped ions is a driven motion that is a consequence of the RF voltage that is used to create the confining potential. This motion inhibits efficient cooling by causing time dependent Doppler shifts and distorting the atomic absorption spectrum. As a consequence, cooling large arrays of ions can be difficult. We discuss two methods for improving cooling in the presence of significant micromotion. The first method is to power broaden and detune the cooling beams, reducing the distorting effects. The second method is to use pulses of Doppler cooling light synchronized with the trap RF, narrowing the range of velocities that must be addressed by the cooling beams.

(Session 5 : Thursday from 5:00 pm - 7:00 pm)