Exotic, topological, and many body localized quantum phase transitions
- Degree Grantor:
- University of California, Santa Barbara. Physics
- Degree Supervisor:
- Cenke Xu
- Place of Publication:
- [Santa Barbara, Calif.]
- Publisher:
- University of California, Santa Barbara
- Creation Date:
- 2016
- Issued Date:
- 2016
- Topics:
- Condensed matter physics
- Keywords:
- Topological order,
Exotic,
Quantum phase transition,
Many body localization,
Symmetry protected, and
Spin liquid - Genres:
- Online resources and Dissertations, Academic
- Dissertation:
- Ph.D.--University of California, Santa Barbara, 2016
- Description:
In this thesis we will study recent examples of exotic, topological, and many body localized quantum phase transitions. In Chapter 2 we study the quantum phase transition between the Z2 spin liquid and valence bond solid (VBS) orders on a triangular lattice. We find a possible nematic Z2 spin liquid intermediate phase and predict a continuous 3d XY* transition to the neighboring columnar and resonating-plaquette VBS phases. In Chapter 3 we demonstrate that an extended Kane-Mele Hubbard model on a bilayer honeycomb lattice has two novel quantum phase transitions. The first is a quantum phase transition between the weakly interacting gapless Dirac fermion phase and a strongly interacting fully gapped and symmetric trivial phase, which cannot be described by the standard Gross-Neveu model. The second is a quantum critical point between a quantum spin Hall insulator with spin Sz conservation and the previously mentioned strongly interacting fully gapped phase. We argue that the first quantum phase transition is related to the Z16 classification of the topological superconductor 3He-B phase with interactions, while the second quantum phase transition is a topological phase transition described by a bosonic O(4) nonlinear sigma model field theory with a Theta-term. In Chapter 4 we propose that if the highest and lowest energy eigenstates of a Hamiltonian belong to different SPT phases, then this Hamiltonian can't be fully many body localized. In Chapter 5 we study the disordered XYZ spin chain and its marginally many body localized critical lines, which we find to be characterized by an effective central charge c'=ln2 and continuously varying critical exponents.
- Physical Description:
- 1 online resource (133 pages)
- Format:
- Text
- Collection(s):
- UCSB electronic theses and dissertations
- Other Versions:
- http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqm&rft_dat=xri:pqdiss:10159746
- ARK:
- ark:/48907/f37m081x
- ISBN:
- 9781369146745
- Catalog System Number:
- 990046969110203776
- Copyright:
- Kevin Slagle, 2016
- Rights:
- In Copyright
- Copyright Holder:
- Kevin Slagle
File | Description |
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Access: Public access | |
Slagle_ucsb_0035D_13021.pdf | pdf (Portable Document Format) |