Quantum phases of a bosonic generalization of the Moore-Read ansatz
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Open Access
Type
ThesisThesis type
Masters by ResearchAuthor/s
Duncan, CameronAbstract
I investigate a generalization of the quantum many-body trial wave-function due to Moore and Read (MR). The generalization extends the fermionic MR wave-function to spin-lattices in non-trivial topological phases. These Spin-MR wave-functions are defined as expectation values of ...
See moreI investigate a generalization of the quantum many-body trial wave-function due to Moore and Read (MR). The generalization extends the fermionic MR wave-function to spin-lattices in non-trivial topological phases. These Spin-MR wave-functions are defined as expectation values of local operators in an auxiliary conformal field theory (CFT). The tensor-network formalism naturally discretizes the functional dependence of a Spin-MR wave-function on its auxiliary theory. I derive within the tensor-network formalism original analytical approximations of Spin-MR expectation values. My approximations map expectation values of Spin-MR states to correlation functions of field theories defined in perturbation theory by the Spin-MR auxiliary CFT. Spin-MR states admit a lattice-gas interpretation as multi-component plasmas: interpreted in this way, my approximations are exact in the dilute, large-system-size limit. I consider families of Spin-MR examples in which the perturbed theory is explicitly solvable, allowing me to show the existence of a phase transition between massive and massless Spin-MR states. I apply my analytical method to calculate the entanglement spectra of example Spin-MR states, including confirmation of a result of Scaffidi and Ringel. Entanglement spectra are important diagnostics of symmetry protected topological (SPT) order. I discuss the usefulness of my analytical method as part of a numerical research program to search for non-trivial SPT order in the space of Spin-MR states.
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See moreI investigate a generalization of the quantum many-body trial wave-function due to Moore and Read (MR). The generalization extends the fermionic MR wave-function to spin-lattices in non-trivial topological phases. These Spin-MR wave-functions are defined as expectation values of local operators in an auxiliary conformal field theory (CFT). The tensor-network formalism naturally discretizes the functional dependence of a Spin-MR wave-function on its auxiliary theory. I derive within the tensor-network formalism original analytical approximations of Spin-MR expectation values. My approximations map expectation values of Spin-MR states to correlation functions of field theories defined in perturbation theory by the Spin-MR auxiliary CFT. Spin-MR states admit a lattice-gas interpretation as multi-component plasmas: interpreted in this way, my approximations are exact in the dilute, large-system-size limit. I consider families of Spin-MR examples in which the perturbed theory is explicitly solvable, allowing me to show the existence of a phase transition between massive and massless Spin-MR states. I apply my analytical method to calculate the entanglement spectra of example Spin-MR states, including confirmation of a result of Scaffidi and Ringel. Entanglement spectra are important diagnostics of symmetry protected topological (SPT) order. I discuss the usefulness of my analytical method as part of a numerical research program to search for non-trivial SPT order in the space of Spin-MR states.
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Date
2018-09-11Licence
The author retains copyright of this thesis. It may only be used for the purposes of research and study. It must not be used for any other purposes and may not be transmitted or shared with others without prior permission.Faculty/School
Faculty of Science, School of PhysicsAwarding institution
The University of SydneyShare