Volume 115, Number 3, August 2016
|Number of page(s)||5|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||13 September 2016|
Topological phase transitions in stanene and stanene-like systems by scaling the spin-orbit coupling
1 College of Science, Nanjing University of Science and Technology - Nanjing 210094, China
2 College of Electronic, Communication and Physics, Shandong University of Science and Technology Qingdao 266590, China
3 Department of Physics and Astronomy, University of Missouri - Columbia, MO 65211-7010, USA
4 Department of Physics, University of Illinois at Urbana-Champaign - 1110 West Green Street, Urbana, IL 61801-3080, USA
5 Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign 104 South Goodwin Avenue, Urbana, IL 61801-2902, USA
Received: 19 May 2016
Accepted: 22 August 2016
We employ first-principles methods to study the topological properties of stanene and stanene-like materials by scaling stanene's natural intrinsic (atomic) spin-orbit-coupling (SOC) strength from 0 to 600%. Quantum phase transitions are observed in this two-dimensional system involving two different gaps. Stanene with zero SOC is a Dirac semimetal with a Dirac cone located at . An infinitesimal SOC opens up a gap at and the system becomes a two-dimensional topological insulator. Increasing the SOC to 333.3% causes the system to become a Dirac semimetal again with a Dirac cone located at . Further increasing the SOC causes a gap opening at , and the system becomes topologically trivial. This behavior is contrasted with that exhibited by three-dimensional topological insulators such as Bi2Se3, for which a strong SOC is a necessary but not a sufficient condition for the formation of topological phases. The similarities and differences are discussed.
PACS: 71.70.Ej – Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect / 73.43.Nq – Quantum phase transitions / 73.61.-r – Electrical properties of specific thin films
© EPLA, 2016
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