Two-dimensional universal conductance fluctuations and the electron-phonon interaction of surface states in Bi2Te2Se microflakes.
The universal conductance fluctuations (UCFs), one of the most important manifestations of mesoscopic electronic interference, have not yet been demonstrated for the two-dimensional surface state of topological insulators (TIs). Even if one delicately suppresses the bulk conductance by improving the quality of TI crystals, the fluctuation of the bulk conductance still keeps competitive and difficult to be separated from the desired UCFs of surface carriers. Here we report on the experimental evidence of the UCFs of the two-dimensional surface state in the bulk insulating Bi2Te2Se microflakes. The solely-B⊥-dependent UCF is achieved and its temperature dependence is investigated. The surface transport is further revealed by weak antilocalizations. Such survived UCFs of the surface states result from the limited dephasing length of the bulk carriers in ternary crystals. The electron-phonon interaction is addressed as a secondary source of the surface state dephasing based on the temperature-dependent scaling behavior.
National Laboratory of Solid State Microstructures, Department of Physics, School of Electronic Science and Engineering, Nanjing University, Nanjing, PR China.
Zhaoguo
Z
Li
Taishi
T
Chen
Haiyang
H
Pan
Fengqi
F
Song
Baigeng
B
Wang
Junhao
J
Han
Yuyuan
Y
Qin
Xuefeng
X
Wang
Rong
R
Zhang
Jianguo
J
Wan
Dingyu
D
Xing
Guanghou
G
Wang