NMR Quantum Information Processing with Para-Hydrogen

TL;DR

This thesis demonstrates the use of para-hydrogen to prepare pure, entangled quantum states for NMR quantum computing, enabling implementation of quantum algorithms and exploring state sharing and entanglement properties.

Contribution

It introduces a method to generate pure, entangled states in liquid state NMR using para-hydrogen, advancing initialization techniques for quantum information processing.

Findings

Prepared pure, entangled states above the entanglement threshold.

Implemented Deutsch and Grover quantum algorithms.

Analyzed state sharing and entanglement preservation.

Abstract

This thesis addresses the problems of initialization and separability in liquid state NMR based quantum information processors. We prepare pure quantum states lying above the entanglement threshold. Our pure state quantum computer derives its purity from the highly polarized nuclear spin states in the para-hydrogen molecule. The thesis begins with a critique of conventional NMR based quantum information processing outlining the major strengths and weaknesses of the technology. We describe the enhanced magnetic ordering of the nuclear spin states in para-hydrogen and an initialization experiment exploiting this effect to achieve pure, entangled states. These states can indeed be used as initial states in implementing quantum algorithms: we describe mplementations of the Deutsch and the Grover quantum algorithms. The "twirl" operation converts a completely arbitrary input state to a Werner singlet. The NMR implementation of this operation is taken up. We also analyze the possibility of sharing the purity of some highly polarized qubits in a quantum computer onto quantum subspaces of arbitrary dimensions, and whether these sharing operations increase or decrease the likelihood of entanglement.