2017/10/31 by Fei Xue, Allan H. MacDonald, A. H. MacDonald · 39 citations
Materials Science · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Coulomb #Electron #Electronic and Structural Properties of Oxides #Hamiltonian (control theory) #Phase transition #Physics #Point reflection #Quantum #Quantum Hall effect #Quantum critical point #Quantum mechanics #Quantum phase transition #Quantum spin Hall effect #Topological Materials and Phenomena #Topological insulator #Topological order #cond-mat.mes-hall #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.120.186802
published in Physical Review Letters 120(18), 186802 (American Physical Society) · 5 pages, 3 figures plus 4 pages supplemental material, accepted for publication in Physical Review Letters
arxiv created 2018/04/27 · openalex publication_date 2018/05/04 · arxiv updated 2018/05/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the phase diagram of a model quantum spin Hall system as a function of band inversion and band-coupling strength, demonstrating that when band hybridization is weak, an interaction-induced nematic insulator state emerges over a wide range of band inversion. This property is a consequence of the long-range Coulomb interaction, which favors interband phase coherence that is weakly dependent on momentum and therefore frustrated by the single-particle Hamiltonian at the band inversion point. For weak band hybridization, interactions convert the continuous gap closing topological phase transition at inversion into a pair of continuous phase transitions bounding a state with broken time-reversal and rotational symmetries. At intermediate band hybridization, the topological phase transition proceeds instead via a quantum anomalous Hall insulator state, whereas at strong hybridization interactions play no role. We comment on the implications of our findings for InAs/GaSb and HgTe/CdTe quantum spin Hall systems.