TY - JOUR
T1 - Quantum oscillations in metallic Sb2Te2Se topological insulator
AU - Shrestha, K.
AU - Marinova, V.
AU - Graf, D.
AU - Lorenz, B.
AU - Chu, C. W.
N1 - Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/2/1
Y1 - 2017/2/1
N2 - We have studied the magnetotransport properties of the metallic, p-type Sb2Te2Se, which is a topological insulator. Magnetoresistance shows Shubnikov-de Haas oscillations in fields above B=15 T. The maxima and minima positions of oscillations measured at different tilt angles with respect to the B direction align with the normal component of field Bcosθ, implying the existence of a two-dimensional Fermi surface in Sb2Te2Se. The value of the Berry phase β determined from a Landau level fan diagram is very close to 0.5, further suggesting that the oscillations result from topological surface states. From Lifshitz-Kosevich analyses, the position of the Fermi level is found to be EF=250 meV, above the Dirac point. This value of EF is almost 3 times larger than that in our previous study on the Bi2Se2.1Te0.9 topological insulator; however, it still touches the tip of the bulk valence band. This explains the metallic behavior and holelike bulk charge carriers in the Sb2Te2Se compound.
AB - We have studied the magnetotransport properties of the metallic, p-type Sb2Te2Se, which is a topological insulator. Magnetoresistance shows Shubnikov-de Haas oscillations in fields above B=15 T. The maxima and minima positions of oscillations measured at different tilt angles with respect to the B direction align with the normal component of field Bcosθ, implying the existence of a two-dimensional Fermi surface in Sb2Te2Se. The value of the Berry phase β determined from a Landau level fan diagram is very close to 0.5, further suggesting that the oscillations result from topological surface states. From Lifshitz-Kosevich analyses, the position of the Fermi level is found to be EF=250 meV, above the Dirac point. This value of EF is almost 3 times larger than that in our previous study on the Bi2Se2.1Te0.9 topological insulator; however, it still touches the tip of the bulk valence band. This explains the metallic behavior and holelike bulk charge carriers in the Sb2Te2Se compound.
UR - http://www.scopus.com/inward/record.url?scp=85013212904&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85013212904&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.95.075102
DO - 10.1103/PhysRevB.95.075102
M3 - Article
AN - SCOPUS:85013212904
VL - 95
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 7
M1 - 075102
ER -