Measurement of Intrinsic Dirac Fermion Cooling on the Surface of the Topological Insulator Bi_2Se_3 Using Time-Resolved and Angle-Resolved Photoemission Spectroscopy
Abstract
We perform time- and angle-resolved photoemission spectroscopy of a prototypical topological insulator (TI) Bi_2Se_3 to study the ultrafast dynamics of surface and bulk electrons after photoexcitation. By analyzing the evolution of surface states and bulk band spectra, we obtain their electronic temperature and chemical potential relaxation dynamics separately. These dynamics reveal strong phonon-assisted surface-bulk coupling at high lattice temperature and total suppression of inelastic scattering between the surface and the bulk at low lattice temperature. In this low temperature regime, the unique cooling of Dirac fermions in TI by acoustic phonons is manifested through a power law dependence of the surface temperature decay rate on carrier density.
Additional Information
© 2012 American Physical Society. Received 11 April 2012. Published 20 September 2012. The authors would like to thank Nathan Gabor and Justin Song for useful discussions and JamesMcIver, Alex Frenzel and Fahad Mahmood for careful reading of the manuscript. This research is supported by Department of Energy Office of Basic Energy Sciences Grant Nos. DE-FG02-08ER46521 and DE-SC0006423 (data acquisition and analysis), Army Research Office (ARO-DURIP) Grant No. W911NF-09-1-0170 (ARTOF spectrometer) and in part by the MRSEC Program of the National Science Foundation under Grant number DMR-0819762 (initial feasibility study). P. J-H. acknowledges support from the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, Early Career Award No. DE. SC0006418 and a Packard Fellowship (material growth and characterization).Attached Files
Published - PhysRevLett.109.127401-1.pdf
Supplemental Material - PRL_BS_trARPES_SOM_r4.pdf
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Additional details
- Alternative title
- Measurement of Intrinsic Dirac Fermion Cooling on the Surface of the Topological Insulator Bi2Se3 Using Time-Resolved and Angle-Resolved Photoemission Spectroscopy
- Eprint ID
- 48503
- Resolver ID
- CaltechAUTHORS:20140813-105943474
- DE-FG02-08ER46521
- Department of Energy (DOE)
- DE-SC0006423
- Department of Energy (DOE)
- W911NF-09-1-0170
- Army Research Office (ARO)
- DMR-0819762
- NSF
- DE-SC0006418
- Department of Energy (DOE)
- David and Lucile Packard Foundation
- Created
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2014-08-13Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field