Browsing Science (Faculty of) by Subject "quantum information"
Now showing items 1-20 of 53
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Causal Models for a Quantum World
(University of Waterloo, 2016-05-18)Quantum mechanics has achieved unparalleled success as an operational theory, describing a wide range of experiments to remarkable accuracy. However, the physical foundations on which it rests remain as puzzling as they ... -
Characterization and Control in Large Hilbert spaces.
(University of Waterloo, 2008-12-03)Computational devices built on and exploiting quantum phenomena have the potential to revolutionize our understanding of computational complexity by being able to solve certain problems faster than the best known classical ... -
Characterization, Verification and Control for Large Quantum Systems
(University of Waterloo, 2015-03-31)Quantum information processing offers potential improvements to a wide range of computing endevaors, including cryptography, chemistry simulations and machine learning. The development of practical quantum information ... -
Classical simulations of quantum systems using stabilizer decompositions
(University of Waterloo, 2021-02-19)One of the state of the art techniques for classically simulating quantum circuits relies on approximating the output state of the circuit by a superposition of stabilizer states. If the number of non-Clifford gates in ... -
Contextuality and Ontological Models: A Tale of Desire and Disappointment
(University of Waterloo, 2019-09-23)Since being defined by Kochen and Specker, and separately by Bell, contextuality has been proposed as one of the key phenomena that distinguishing quantum theory from classical theories. However, with the rise of quantum ... -
Controlling Quantum Information Devices
(University of Waterloo, 2012-06-18)Quantum information and quantum computation are linked by a common mathematical and physical framework of quantum mechanics. The manipulation of the predicted dynamics and its optimization is known as quantum control. Many ... -
Design and construction of an ion trapping apparatus for quantum simulation experiments
(University of Waterloo, 2019-09-26)The trapped ions platform represents an excellent framework for Quantum information science experiments. Long coherence times, extremely high state initialization and detection fidelity, inherent full-connectivity between ... -
Developing a Generalized Model for Neutron Diffraction with Quantum Information Theory
(University of Waterloo, 2022-08-31)Due to their high mass and neutral electric charge, neutrons are often used at low energies to probe small-scale structures or measure fundamental constants of nature. To design neutron optical elements for use in these ... -
Engineering Effective Hamiltonians for Magnetic Resonance
(University of Waterloo, 2019-07-22)Effective Hamiltonian engineering is a powerful technique that utilises time-dependent perturbation theory to suppress or enhance certain effects that arise from otherwise weak Hamiltonian terms, when an experimenter ... -
Entanglement in Non-inertial Frames
(University of Waterloo, 2008-09-19)This thesis considers entanglement, an important resource for quantum information processing tasks, while taking into account the theory of relativity. Not only is this a more complete description of quantum information, ... -
Entanglement quantification and quantum benchmarking of optical communication devices
(University of Waterloo, 2012-04-27)In this thesis, we develop a number of operational tests and tools for benchmarking the quantum nature of optical quantum communication devices. Using the laws of quantum physics, ideal quantum devices can fundamentally ... -
Estimating and Mitigating Effects of Space Radiation Damage in Single-Photon Avalanche Diodes
(University of Waterloo, 2022-02-01)Satellite-based quantum key distribution necessitates practical and robust detectors capable of withstanding the harsh environment of space. Single-photon avalanche diodes (SPADs) have been shown to fulfill the required ... -
An estimation theoretic approach to quantum realizability problems
(University of Waterloo, 2023-09-27)This thesis seeks to develop a general method for solving so-called quantum realizability problems, which are questions of the following form: under which conditions does there exist a quantum state exhibiting a given ... -
Experimental and theoretical demonstration of the feasibility of global quantum cryptography using satellites
(University of Waterloo, 2014-10-15)Information security is a growing concern in our modern world, where almost everything can be done online. To protect security, classical encryption protocols, such as RSA, are used. These encryption protocols are almost ... -
Experimental prospects for detecting the quantum nature of spacetime
(University of Waterloo, 2017-09-21)This thesis is concerned with advancing the confrontation between relativistic quantum information (RQI) and experiment. We investigate the lessons that some present-day experiments can teach us about the relationship ... -
Experimental quantum communication in demanding regimes
(University of Waterloo, 2011-08-02)Quantum communication promises to outperform its classical counterparts and enable protocols previously impossible. Specifically, quantum key distribution (QKD) allows a cryptographic key to be shared between distant parties ... -
Experimental Quantum Information Processing with Photons
(University of Waterloo, 2013-08-30)This thesis describes experimental generation, manipulation and measurement of quantum information using photon pairs emitted in bulk crystals. Multi-photon sources engineered during the course of this thesis have proven ... -
Experiments with Generalized Quantum Measurements and Entangled Photon Pairs
(University of Waterloo, 2009-11-02)This thesis describes a linear-optical device for performing generalized quantum measurements on quantum bits (qubits) encoded in photon polarization, the implementation of said device, and its use in two diff erent but ... -
Few Hole Quantum Dots in a Gated GaAs/AlGaAs Heterostructure
(University of Waterloo, 2019-06-24)This thesis presents a set of experiments that explore gate de ned hole quantum dots in the GaAs/AlGaAs heterostructure. These experiments explore the evolution of the quantum states of holes in a double quantum dot. The ... -
Flag Fault-Tolerant Error Correction with Qudits
(University of Waterloo, 2022-01-20)In this thesis, I explore fault-tolerant quantum error correction using qudits. I show that a specific flag-fault-tolerant procedure for the five-qubit code may be extended to work on the five qudit code for any prime ...