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Title: Time-resolved orbital angular momentum spectroscopy

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4927321· OSTI ID:22486345
;  [1]
  1. Department of Physics and Astronomy, The University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

We introduce pump-probe magneto-orbital spectroscopy, wherein Laguerre-Gauss optical pump pulses impart orbital angular momentum to the electronic states of a material and subsequent dynamics are studied with 100 fs time resolution. The excitation uses vortex modes that distribute angular momentum over a macroscopic area determined by the spot size, and the optical probe studies the chiral imbalance of vortex modes reflected off the sample. First observations in bulk GaAs yield transients that evolve on time scales distinctly different from population and spin relaxation, as expected, but with surprisingly large lifetimes.

OSTI ID:
22486345
Journal Information:
Applied Physics Letters, Vol. 107, Issue 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English