Quantum interference in macroscopic crystals of nonmetallic Bi2Se3.
Photoemission experiments have shown that Bi2Se3 is a topological insulator. By controlled doping, we have obtained crystals of Bi2Se3 with nonmetallic conduction. At low temperatures, we uncover a novel type of magnetofingerprint signal which involves the spin degrees of freedom. Given the mm-sized crystals, the observed amplitude is 200-500x larger than expected from universal conductance fluctuations. The results point to very long phase-breaking lengths in an unusual conductance channel in these nonmetallic samples. We discuss the nature of the in-gap conducting states and their relation to the topological surface states.
Checkelsky
J G
JG
Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
Hor
Y S
YS
Liu
M-H
MH
Qu
D-X
DX
Cava
R J
RJ
Ong
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NP