2017/06/30 by K. Shrestha, D. Graf, David Graf +4
Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Geometry #Magnetic field #Magnetoresistance #Materials science #Physics #Quantum many-body systems #Quantum mechanics #Surface (topology) #Surface states #Topological Materials and Phenomena #Topological insulator #Weak localization #cond-mat.str-el
paper · pdf · doi:10.1063/1.4997947
published as J. Appl. Phys. 122, 145901 (2017) · 5 pages, 4 figures
arxiv created 2017/10/11 · openalex publication_date 2017/10/11 · arxiv updated 2017/10/12 · openalex created_date 2017/10/20 · openalex updated_date 2026/08/06
We have investigated the weak antilocalization (WAL) effect in the p-type Bi2Se2.1Te0.9 topological system. The magnetoconductance shows a cusp-like feature at low magnetic fields, indicating the presence of the WAL effect. The WAL curves measured at different tilt angles merge together when they are plotted as a function of the normal field components, showing that surface states dominate the magnetoconductance in the Bi2Se2.1Te0.9 crystal. We have calculated magnetoconductance per conduction channel and applied the Hikami-Larkin-Nagaoka formula to determine the physical parameters that characterize the WAL effect. The number of conduction channels and the phase coherence length do not change with temperature up to T = 5 K. In addition, the sample shows a large positive magnetoresistance that reaches 1900% under a magnetic field of 35 T at T = 0.33 K with no sign of saturation. The magnetoresistance value decreases with both increasing temperature and tilt angle of the sample surface with respect to the magnetic field. The large magnetoresistance of topological insulators can be utilized in future technology such as sensors and memory devices.