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Disentangling surface state formation in topological insulators

Scientific Achievement
First real time mapping of the formation of topologically protected surface states (TSS) reveals surprising new spin-polarized unoccupied surface resonance states (USR) in Bi2Se3.

Significance and Impact
These states highlight how spin-orbit coupling shapes the properties of the surface in a new class of materials that can revolutionize computing.

Research Details

  • A transient state is created in a topological insulator after an excitation by an infrared laser and measured with a ultraviolet probe.
  • A unique spin-, time- and angle resolved photoelectron spectrometer images the spin dependent electronic population.
  • Calculations show that the unoccupied surface resonances are remnants of Rashba states that would exist in a trivial insulator.

C. Jozwiak, J. Sobota, K. Gotlieb, A. Kemper, C. Rotundu, R. Birgenau, Z. Hussain, D.-H. Lee, Z.-X. Shen, A. Lanzara. Nature Com. 7, 13143 (2016) DOI: 10.1038/ncomms13143