Facio JI, Efremov D, Koepernik K, You JS, Sodemann I, van den Brink J. Strongly Enhanced Berry Dipole at Topological Phase Transitions in BiTeI.
PHYSICAL REVIEW LETTERS 2018;
121:246403. [PMID:
30608737 DOI:
10.1103/physrevlett.121.246403]
[Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Indexed: 06/09/2023]
Abstract
Transitions between topologically distinct electronic states have been predicted in different classes of materials and observed in some. A major goal is the identification of measurable properties that directly expose the topological nature of such transitions. Here, we focus on the giant Rashba material bismuth tellurium iodine which exhibits a pressure-driven phase transition between topological and trivial insulators in three dimensions. We demonstrate that this transition, which proceeds through an intermediate Weyl semimetallic state, is accompanied by a giant enhancement of the Berry curvature dipole which can be probed in transport and optoelectronic experiments. From first-principles calculations, we show that the Berry dipole-a vector along the polar axis of this material-has opposite orientations in the trivial and topological insulating phases and peaks at the insulator-to-Weyl critical points, at which the nonlinear Hall conductivity can increase by over 2 orders of magnitude.
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