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Author ORCID Identifier
Open Access Dissertation
Doctor of Philosophy (PhD)
Year Degree Awarded
Month Degree Awarded
Condensed Matter Physics | Quantum Physics | Statistical, Nonlinear, and Soft Matter Physics
Quantum criticality in low-dimensional quantum systems is known to host exotic behaviors. In quantum one-dimension (1D), the emerging conformal group contains infinite generators, and conformal techniques, e.g., operator product expansion, give accurate and universal descriptions of underlying systems. In quantum two-dimension (2D), the electronic interaction causes singular corrections to Fermi-liquids characteristics. Meanwhile, the Dirac fermions in topological 2D materials can greatly enrich emerging phenomena. In this thesis, we study the symmetry-breaking effects of low-dimensional quantum criticality. In 1D, we consider two cases: time-reversal symmetry (TRS) breaking in the Majorana conformal field theory (CFT) and the absence of conformal symmetry in the $z=2$ Lifshitz criticality. In both cases, universal features of quantum criticality exhibit exotic behaviors, e.g., the finite-size amplitude and entanglement entropy. In 2D, we study the effect of a weak perpendicular magnetic field on the doped graphene. We establish the chiral symmetry breaking mechanism induced by the field and explore its many-body consequences, e.g., thermodynamics and magnetoresistance.
Wang, Ke, "Symmetry Breaking Effects in Low-Dimensional Quantum Systems" (2022). Doctoral Dissertations. 2688.
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