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arXiv · 1203.3616

Ultrafast Optical Excitation of a Persistent Surface-State Population in the Topological Insulator Bi2Se3

Jonathan A. Sobota·Shuolong Yang·James G. Analytis·Yulin Chen·Ian R. Fisher·Patrick S. Kirchmann·Z. -X. Shen
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Abstract

Using femtosecond time- and angle- resolved photoemission spectroscopy, we investigated the nonequilibrium dynamics of the topological insulator Bi2Se3. We studied p-type Bi2Se3, in which the metallic Dirac surface state and bulk conduction bands are unoccupied. Optical excitation leads to a meta-stable population at the bulk conduction band edge, which feeds a nonequilibrium population of the surface state persisting for >10ps. This unusually long-lived population of a metallic Dirac surface state with spin texture may present a channel in which to drive transient spin-polarized currents.

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Jonathan A. Sobota, Shuolong Yang, James G. Analytis, Yulin Chen, Ian R. Fisher, Patrick S. Kirchmann, Z. -X. Shen. 2012-03-16. Ultrafast Optical Excitation of a Persistent Surface-State Population in the Topological Insulator Bi2Se3. https://doi.org/10.1103/physrevlett.108.117403

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