biostudies-literatureUnknown111(40)Zhou MFormation of topological quantum phase on a conventional semiconductor surface is of both scientific and technological interest. Here, we demonstrate epitaxial growth of 2D topological insulator, i.e., quantum spin Hall state, on Si(111) surface with a large energy gap, based on first-principles calculations. We show that the Si(111) surface functionalized with one-third monolayer of halogen atoms [Si(111)-√3 x √3 -X (X = Cl, Br, I)] exhibiting a trigonal superstructure provides an ideal template for epitaxial growth of heavy metals, such as Bi, which self-assemble into a hexagonal lattice with high kinetic and thermodynamic stability. Most remarkably, the Bi overlayer is atomically bonded to but electronically decoupled from the underlying Si substrate, exhibiting isolated quantum spin HaProceedings of the National Academy of Sciences of the United States of America14378-81https://www.ebi.ac.uk/biostudies/studies/S-EPMC4210051biostudies-literatureEpitaxial growth of large-gap quantum spin Hall insulator on semiconductor surface.PMC4210051Zhou MLiu ZLi PMing WWang ZLiu FfalseEpitaxial growth of large-gap quantum spin Hall insulator on semiconductor surface.Formation of topological quantum phase on a conventional semiconductor surface is of both scientific and technological interest. Here, we demonstrate epitaxial growth of 2D topological insulator, i.e., quantum spin Hall state, on Si(111) surface with a large energy gap, based on first-principles calculations. We show that the Si(111) surface functionalized with one-third monolayer of halogen atoms [Si(111)-√3 x √3 -X (X = Cl, Br, I)] exhibiting a trigonal superstructure provides an ideal template for epitaxial growth of heavy metals, such as Bi, which self-assemble into a hexagonal lattice with high kinetic and thermodynamic stability. Most remarkably, the Bi overlayer is atomically bonded to but electronically decoupled from the underlying Si substrate, exhibiting isolated quantum spin Ha2014-01-01T00:00:00Z2014 Oct2025-04-22T21:08:31.666Z2019-03-27T01:38:22ZS-EPMC42100512524658410.1073/pnas.1409701111