IAMS Lecture on September 6, 10:00am, Dr. Poe Lecture Hall, Prof. Boris Blinov

IAMS Lecture Announcement
Title: Two-dimensional trapped ion crystals, micromotion and qubit state detection
Speaker: Prof. Boris Blinov (Department of Physics, University of Washington, USA)
Time: 10:00 AM, September 6 (Wednesday), 2023
Place: Dr. Poe Lecture Hall, IAMS (本所浦大邦講堂臺大校園內)
Contact: Dr. Ming-Shien Chang 張銘顯博士
To study potential avenues for scaling up trapped ion crystal size, we built a modified Paul trap with an oblate aspect ratio designed for trapping radial 2-d ion crystals. In this geometry, the micromotion can only be minimized in the axial direction, transverse to the crystal plane. The in-plane micromotion is unavoidable, its amplitude increasing linearly with distance from the trap center. Thus, different ions in a large crystal experience different micromotion amplitudes, and different Doppler shifts, making traditional laser cooling techniques inefficient. We explored two avenues towards improving the laser cooling efficiency: the two-tone laser cooling and the micromotion-synchronized pulsed Doppler cooling, allowing us to stabilize larger 2-d crystals than with the traditional Doppler cooling.
These experiments were enabled in part by the novel imaging system based on a CMOS camera that allows 1.5 ns temporal resolution of single photon detection. Direct observation of the trapped ion micromotion is attainable with this camera, leading to a simplified way of micromotion detection and compensation. We also demonstrated how this camera can be used for robust, low crosstalk detection of a trapped Ba+ ion qubit register, with average single-qubit detection error of 4.2(1.5) ppm and a four-qubit state detection error of 17(2) ppm, limited by the decay lifetime of the qubit.

聯絡人:陳文慧小姐 02-2366-8275