1College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
2Beijing Computational Science Research Center, Beijing 100193, China
Nano-Micro Conference, 2017, 1, 01064
Published Online: 30 October 2017 (Abstract)
Citation Information: Yan-Chao Li, Quantum phase transitions and order parameters of a topological insulator. Nano-Micro Conference, 2017, 1, 01064 doi: 10.11605/cp.nmc2017.01064
Received: 15 May 2017, Accepted: 10 June 2017, Published Online: 30 October 2017
Using quantum entanglement, quantum coherence, and the reduced density matrix, we study the quantum phase transitions and propose order parameters for the phases of a topological insulator, specifically a spinless Su-Schrieffer-Heeger (SSH) model, and consider the effect of short-range interactions. All the derived order parameters and their possible corresponding quantum phases are verified by the entanglement entropy and electronic configuration analysis results. The order parameter appropriate to the topological regions is further proved by calculating the Berry phase under twisted boundary conditions. It is found that the topological nontrivial phase is robust to the introduction of repulsive intersite interactions and can appear in the topological trivial parameter region when appropriate interactions are added.
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