Progress towards generating a 3D Cluster State in a neutral atom quantum computer

Open Access
- Author:
- Giraldo Mejia, Felipe
- Graduate Program:
- Physics
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- July 22, 2022
- Committee Members:
- Zhiwen Liu, Outside Unit & Field Member
David Weiss, Chair & Dissertation Advisor
Kurt Gibble, Major Field Member
Jorge Sofo, Major Field Member
Nitin Samarth, Program Head/Chair - Keywords:
- Quantum computing
Neutral Atoms
Cluster States
Quantum Information
Atomic Physics
Electromagnetically Induced Transparency
Quantum Error Correction - Abstract:
- Entanglement, which means that particles can be correlated to a higher degree than is classically allowed, is a key feature of quantum mechanics. Highly entangled states are important resources for quantum technologies. They can potentially enhance sensing and cryptography, and in quantum computers, allow for information processing at exponential speeds compared to classical computers. A particularly interesting highly entangled state known as a Cluster State has been theoretically predicted to be resilient against errors and imperfections. The main part of this thesis is devoted to our efforts of creating a 3D Cluster State in our neutral atom quantum computer through ultra-cold collisions. To have high fidelity entangling operations through these ultra-cold collisions, we have set up a new set of qubits at a higher magnetic field and a two-photon transition between them. Additionally, we have enhanced our vibrational cooling. We have also explored different possibilities for creating the Cluster State through our entangling operation using a spin-echo structure, which will make the operation more robust. Finally, we have taken preliminary data with the collisional states and devised a plan to remove magnetic field noise in the future to implement the entangling operation. The second part of this thesis delves into a theoretical proposal to measure a subset of qubits without affecting the surrounding ones in neutral atom quantum computers using electromagnetically-induced transparency (EIT). The basis of this proposal is setting up state-selective EIT, which allows some atoms to be imaged while protecting the rest. We investigate in detail three different schemes that would allow for this type of measurement. We reveal the feasibility of this approach, as these schemes only require neutral atom quantum computers one additional beam in order to be implemented. We also explicitly show that the best of these schemes works even with realistic experimental imperfections and can naturally incorporate cooling of the imaged atoms.