Planar Hall effect (PHE) in topological insulators (TIs) is discussed as an effect that stems mostly from conduction due to topologically protected surface states. Although surface states play a critical role and are of utmost importance in TIs, our present study in Bi 2 Te 3 thin films reflects the need for considering the bulk conduction in understanding the origin of PHE in TIs. This necessity emerges from our observation of an unconventional increase in the PHE signal with TI thickness and temperature where the bulk effect takes over. Here, we find an enhancement in the PHE amplitude by doubling the Bi 2 Te 3 film-thickness on the Si (111) substrate-from % 1.9 nX m in 14 quintuple layer (QL) to % 3.1 nX m in 30 QL devices at B ¼ 5 T. Also, the PHE amplitude in the 30 QL Bi 2 Te 3 films grown on two different substrates, viz., Si (111) and Al 2 O 3 (0001), shows an increase with temperature. Our experiments indicate that the contribution of bulk states to PHE in TIs could be significant.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.