Browsing Masters Degrees (Physics) by Subject "Quantum theory."
Now showing items 1-12 of 12
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Constant-temperature dynamics in the Wigner representation of quantum mechanics.
(2011)This dissertation deals with theory and algorithms for computer simulations of classical and quantum systems in the canonical ensemble. First, the approach of Nos e-Hoover and its generalization, known as the Nos e- Hoover ... -
The implementation of polarisation encoded quantum key distribution in fibre.
(2012)Quantum Key Distribution (QKD) employs the laws of quantum mechanics for the purpose of cryptography. Two parties, commonly called Alice and Bob, are able to share a random key which is used to encrypt a message. Any ... -
Implementing Grover's search algorithm using the one-way quantum computing model and photonic orbital angular momentum.
(2011)Standard quantum computation proceeds via the unitary evolution of physical qubits (two-level systems) that carry the information. A remarkably different model is one-way quantum computing where a quantum algorithm is ... -
Monitoring the states of single quantum systems.
(2012)Continuous weak measurement provide a convenient way to gather information about a quantum system without the need to prepare huge ensembles of identical systems as required by standard quantum measurement theory. Even ... -
Monte Carlo simulations in open quantum systems.
(2007)The motivation for this Masters thesis is to develop numerical algorithms to study the dynamical evolution of non-Markovian open quantum systems. Such systems are of importance if one is interested in modeling solid state ... -
Numerical sampling of nonadiabatic dynamics of quantum-classical systems.
(2010)The simulation of the dynamics of quantum systems is very di cult, due to the fact that, in general, it cannot be calculated exactly for interacting many-body systems. Brute force simulations of quantum dynamics are ... -
On non-Hermitian quantum mechanics.
(2013)The purpose of this dissertation is to review the salient features of non-Hermitian quantum mechanics. An introduction to Hermitian quantum mechanics is included to make this review as accessible as possible. Attempts ... -
Quantum dynamics in classical constant-temperature baths.
(2012)In this dissertation the formulation of various integration algorithms is studied, with a view to simulate quantum-classical systems in contact with a thermal bath. In particular focus is given to the constant temperature ... -
Quantum dynamics in the partial Wigner picture.
(2013)The Wigner formalism can be used to provide a representation of quantum dynamics in a classical-like phase space. However, there are many cases, such as when dealing with spin systems in a dissipative environment, in ... -
Security and entanglement in differential-phase-shift quantum key distribution.
(2009)Quantum key distribution (QKD) aims at the creation of a secret key in the two locations of partners, traditionally Alice and Bob, wishing to communicate in private. A generic QKD protocol utilises a quantum channel and ... -
Simple qubit systems in bosonic baths.
(2010)The study is focused on the thermal entanglement of spin chains. Chains consisting of two and three qubits are considered. These chains are considered open because they are coupled to bosonic baths at different temperatures. ...