Alexandria Digital Research Library

Three-dimensional frustrated quantum magnets

Author:
Lee, SungBin
Degree Grantor:
University of California, Santa Barbara. Physics
Degree Supervisor:
Leon Balents
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2012
Issued Date:
2012
Topics:
Physics, General and Physics, Condensed Matter
Keywords:
Spinel
Frustrated magnets
Spin liquids
Quantum spin ice
Columbite
Pyrochlore
Genres:
Dissertations, Academic and Online resources
Dissertation:
Ph.D.--University of California, Santa Barbara, 2012
Description:

Frustration, induced by competition between different interactions, can be realized on a diamond lattice, especially in A-site of spinel materials with a chemical formula AB2X 4. We address the realization of classical spin liquid and provide a unified theoretical explanation of various phenomena observed in spinel materials.

Motivated by CoNb2O6, we study interplay between quantum criticality and geometric frustration. In the presence of carefully oriented magnetic field, the system realizes quantum phase transition of transverse field quantum Ising model while magnetic frustration exists due to the lattice geometry at the same time. We reveal several quantum magnetic phases and crossovers between one dimensional quantum criticality and several three dimensional quantum critical points.

Lastly, we look for the possible realization of a quantum spin liquid focusing on A-site magnets in rare-earth pyrochlores. Based on a pseudospin-1/2 Hamiltonian, we discuss how quantum fluctuations lead the exotic phases such as a U(1) quantum spin liquid and XY ordered phases, beyond classical spin ice state.

Physical Description:
1 online resource (167 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f3c24tdq
ISBN:
9781267768100
Catalog System Number:
990039147710203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
SungBin Lee
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