Towards synthetic Rydberg lattices with optical tweezer arrays

Ang'Ong'A, Jackson

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https://hdl.handle.net/2142/113792 Copy

Description

Title

Towards synthetic Rydberg lattices with optical tweezer arrays

Author(s)

Ang'Ong'A, Jackson

Issue Date

2021-07-21

Director of Research (if dissertation) or Advisor (if thesis)

Gadway, Bryce

Doctoral Committee Chair(s)

Lorenz, Virginia

Committee Member(s)

• Madhavan, Vidya
• Kwiat, Paul

Department of Study

Physics

Discipline

Physics

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Tweezer array, potassium, single atoms, gray-molasses

Abstract

Trapped neutral atoms in optical tweezers have emerged as a viable platform for quantum simulation, metrology and quantum information processing due to their simple design yet versatile application. Recent developments in loading, cooling and re-arrangement techniques have been combined with Rydberg interactions and have led to insightful studies of quantum many-body phenomena based on analog simulation of Ising and XY models. So far, such systems have mostly been limited to interactions that involve one or two Rydberg states. Concurrently, synthetic lattices have also emerged as a viable platform for quantum simulation of many-body systems through site-by-site engineering of many-body Hamiltonians. Synthetic lattices feature both full spectroscopic control and tunability of every single-body term in the simulated Hamiltonian and thereby enable a bottom-up approach to studying emergent phenomena when combined with interactions. In our experiment, we bring the idea of synthetic lattices to a system of potassium atoms trapped in optical tweezer arrays, where tweezer-trapped atoms are excited to a Rydberg state followed by applying multi-tone microwave fields to drive transitions to neighboring Rydberg levels. While such a synthetic lattice can be used to study topology and disorder in 1D, our system allows us to bring Rydberg interaction into the picture and study the interplay between topology, disorder and interactions. One novel phenomenon that has been identified to appear in such a system is the spontaneous formation of quantum strings in the synthetic dimension. This work also presents some technical studies on cooling and imaging of single atoms in optical tweezers in preparation for Rydberg excitation. Specifically, we demonstrate a simple approach to in-trap imaging which involves using a near-detuned (780 nm) optical tweezer, which leads to relatively minor differential (ground vs. excited state) Stark shifts. We demonstrate that simple and robust loading, cooling, and imaging can be achieved through a combined addressing of the D1 (770 nm) and D2 (767 nm) transitions. While imaging on the D2 transition, we can simultaneously apply Λ-enhanced gray molasses (GM) on the D1 transition, preserving low backgrounds for single-atom imaging through spectral filtering. Using D1 cooling during and after trap loading, we demonstrate enhanced (75%) loading efficiencies as well as cooling to low temperatures (≈ 15 μK). These results suggest a simple and robust path for loading and cooling large arrays of potassium atoms in optical tweezers, through the use of resource-efficient near-detuned optical tweezers and GM cooling.

Graduation Semester

2021-12

Type of Resource

Thesis

Permalink

http://hdl.handle.net/2142/113792

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Copyright 2021 Jackson Ang'Ong'A

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