Topological phase transition and quantum spin Hall edge states of antimony few layers.
While two-dimensional (2D) topological insulators (TI's) initiated the field of topological materials, only very few materials were discovered to date and the direct access to their quantum spin Hall edge states has been challenging due to material issues. Here, we introduce a new 2D TI material, Sb few layer films. Electronic structures of ultrathin Sb islands grown on Bi2Te2Se are investigated by scanning tunneling microscopy. The maps of local density of states clearly identify robust edge electronic states over the thickness of three bilayers in clear contrast to thinner islands. This indicates that topological edge states emerge through a 2D topological phase transition predicted between three and four bilayer films in recent theory. The non-trivial phase transition and edge states are confirmed for epitaxial films by extensive density-functional-theory calculations. This work provides an important material platform to exploit microscopic aspects of the quantum spin Hall phase and its quantum phase transition.
Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Republic of Korea.|Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Sung Hwan
SH
Kim
Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Kyung-Hwan
KH
Jin
Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Joonbum
J
Park
Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Jun Sung
JS
Kim
Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Seung-Hoon
SH
Jhi
Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Republic of Korea.|Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Han Woong
HW
Yeom