On Experimental Deterministic Quantum Computation with One Quantum Bit (DQC1)

Abstract

Quantum information processors have the ability to drastically change our world. By manipulating bits of information ruled by the laws of quantum mechanics, computational devices can perform some computations that are classically intractable. Most quantum algorithms rely on pure qubits as inputs and require entanglement throughout the computation. In this thesis, we explore a model of computation that uses mixed qubits without entanglement known as DQC1 (deterministic quantum computation with one quantum bit), using the physical system of liquid-state Nuclear Magnetic Resonance (NMR). Throughout our research, we experimentally implement an algorithm that completely encapsulates the DQC1 model, and take a close look at the quantum nature of DQC1-states as given by the quantum discord and geometric quantum discord, which are measures of non-classicality that capture correlations weaker than those measured by entanglement. We experimentally detect and quantify these correlations in an NMR DQC1 quantum information processor.