# Quantum Entanglement Distribution in Networks: PhD Defense
> Explore a PhD defense on optimizing fidelity and throughput in quantum networks via repeater protocols. Analysis of decoherence and experimental setups.

Tags: quantum-computing, physics, phd-defense, quantum-networks, research-presentation, academic-template, science
## Entanglement Distribution in Quantum Networks
* **Candidate**: Alex K. Thorne, Center for Quantum Information (Jan 14, 2026).
* **Objective**: Optimizing fidelity and throughput via repeater protocols.

## The Challenge: Decoherence
* Quantum state transmission is limited by the No-Cloning Theorem and photon loss.
* Highlighted the need for robust quantum repeaters to bridge gaps over 100km.

## Literature Review & Current Gaps
* **Identified Gap**: Lack of scalable, ground-based architecture with >98% fidelity without cryogenic memory.
* **Existing methods**: Trusted Node Networks, DLCZ Protocol, and Satellite QKD.

## Theoretical & Experimental Architecture
* **Setup**: Spontaneous parametric down-conversion (SPDC) source with trapped-ion memory nodes.
* **Visualization**: Qubit states represented on the Bloch Sphere; decoherence shown as vector shrinking.

## Results & Analysis
* **Fidelity Decay**: Optimized Dynamic Decoupling (ODD) protocol maintains ~0.82 fidelity at 60μs compared to <0.2 for standard memory.
* **Interference Visibility**: Visibility of V = 94.5 ± 0.3% achieved in Hong-Ou-Mandel experiments.

## Summary of Contributions
* **Theoretical**: New error-correcting model for lossy channels.
* **Experimental**: 2x increase in fidelity for trapped-ion systems.
* **Impact**: Provides foundation for 500km+ quantum repeater links.
---
This presentation was created with [Bobr AI](https://bobr.ai) — an AI presentation generator.