Southwest Quantum Information and Technology

Projection of pinhole diffraction trap array into cold atom cloud for quantum computing using atomic qubits

Presenting Author: Sergio Aguayo, California Polytechnic State University
Contributing Author(s): Alexandra Crawford, Justin Jee, Katharina Gillen

Creating a quantum computer requires a system of particles that can be well-controlled to achieve quantum operations. We need a large array of qubits with long coherence times, which can be initialized, operated on by single and two qubit gates, and read out. For neutral atoms, the qubit states are stable ground states that interact minimally with the environment, leading to long coherence times. Experimentally, the qubits are manipulated using carefully timed laser beam pulses with controlled frequency and intensity. The outstanding issue is finding a light pattern that can hold an array of individually addressable atoms to perform these quantum operations. To solve this, we investigate making a 2D array of qubits using pinhole diffraction patterns, which have localized bright and dark spots, serving as atomic light traps. We are preparing to fill these traps in our cold atom lab. To transfer atoms, we project the diffraction patterns from a single pinhole or a pinhole array into a cloud of cold Rb atoms formed by a magneto-optical trap (MOT). We built an injection-locked diode laser system for the light traps, installed acousto-optical modulators and mechanical shutters to turn the laser beams on and off, designed and implemented an electrical circuit for switching the MOT magnets on and off quickly, and developed an imaging system to record the cloud shape and fluorescence signal of the trapped atoms in order to measure their number and the trap lifetime and frequencies.

Read this article online: http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1328&context=phy_fac

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