@article{f0d1d05b77fa435d8fc9f2e73b13c717,
title = "Signatures of long-range-correlated disorder in the magnetotransport of ultrathin topological insulators",
abstract = "In an ultrathin topological insulator (TI) film, a hybridization gap opens in the TI surface states, and the system is expected to become either a trivial insulator or a quantum spin Hall insulator when the chemical potential is within the hybridization gap. Here we show, however, that these insulating states are destroyed by the presence of a large and long-range-correlated disorder potential, which converts the expected insulator into a metal. We perform transport measurements in ultrathin dual-gated topological insulator films as a function of temperature, gate voltage, and magnetic field, and we observe a metalliclike nonquantized conductivity, which exhibits a weak antilocalizationlike cusp at low magnetic fields and gives way to a nonsaturating linear magnetoresistance at large fields. We explain these results by considering the disordered network of electron- and hole-type puddles induced by charged impurities. We argue theoretically that such disorder can produce an insulator-to-metal transition as a function of increasing disorder strength, and we derive a condition on the band gap and the impurity concentration necessary to observe the insulating state. We also explain the linear magnetoresistance in terms of strong spatial fluctuations of the local conductivity using both numerical simulations and a theoretical scaling argument.",
author = "D. Nandi and B. Skinner and Lee, {G. H.} and Huang, {K. F.} and K. Shain and Chang, {Cui Zu} and Y. Ou and Lee, {S. P.} and J. Ward and Moodera, {J. S.} and P. Kim and Halperin, {B. I.} and A. Yacoby",
note = "Funding Information: It is a pleasure to thank I. Sodemann, A. Nahum, S. Simon, J. T. Chalker, A. Kamenev, and Y. P. Chen for valuable discussions. We are indebted to D. Wei, L. Orona, T. Zhou, C. B{\o}ttcher, M. Kosowsky, and A. Pierce for invaluable help with fabrication and measurements. A.Y., D.N., K.S., and J.W. acknowledge support from Gordon and Betty Moore Foundation Grant No. 4531, NSF Grant No. DMR-1708688, ARO Grant No. W911NF16-1-0491, ARO Grant No. W911NF-17-1-0023, and ARO Grant No. W911NF-18-1-0316. Fabrication for this work was supported by DOE Award No. DE-SC0001819. B.S. was supported as part of the MIT Center for Excitonics, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No. DE-SC0001088. B.I.H. acknowledges support from the STC Center for Integrated Quantum Materials under NSF Grant No. DMR-1231319. P.K., G.H.L., and K.-F.H. acknowledge support from NSF Grant No. DMR-1420634. J.S.M., C.-Z.C., and Y.O. acknowledge support from NSF Grant No. DMR-1700137, ONR Grant No. N00014-16-1-2657, and the Center for Integrated Quantum Materials under NSF Grant No. DMR-1231319. C.-Z.C. also acknowledges support from an Alfred P. Sloan Research Fellowship and ARO Young Investigator Program Award (Award No. W911NF1810198). Publisher Copyright: {\textcopyright} 2018 American Physical Society.",
year = "2018",
month = dec,
day = "19",
doi = "10.1103/PhysRevB.98.214203",
language = "English (US)",
volume = "98",
journal = "Physical Review B-Condensed Matter",
issn = "2469-9950",
publisher = "American Physical Society",
number = "21",
}