Ultrafast optical excitation of a persistent surface-state population in the topological insulator Bi2Se3.

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 metastab...

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מידע ביבליוגרפי
Main Authors: Sobota, J, Yang, S, Analytis, J, Chen, Y, Fisher, I, Kirchmann, P, Shen, Z
פורמט: Journal article
שפה:English
יצא לאור: 2012
תיאור
סיכום: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 metastable population at the bulk conduction band edge, which feeds a nonequilibrium population of the surface state persisting for >10 ps. 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.