TY - JOUR
T1 - Anisotropic attosecond charge carrier dynamics and layer decoupling in quasi-2D layered
AU - Eads, Calley N.
AU - Bandak, Dmytro
AU - Neupane, Mahesh R.
AU - Nordlund, Dennis
AU - Monti, Oliver L.A.
N1 - Funding Information:
This work was supported by the National Science Foundation, award numbers CHE 1213243 and CHE 1565497. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. M.R.N. also acknowledges the support by grants of computer time from the DOD High Performance Computing Modernization Program at the U.S. Air Force Research Laboratory and U.S. Army Engineer Research and Development Center DOD Supercomputing Resource Centers. The authors thank Bruce Parkinson for providing the bulk SnS2 crystals.
Publisher Copyright:
© 2017 The Author(s).
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Strong quantum confinement effects lead to striking new physics in two-dimensional materials such as graphene or transition metal dichalcogenides. While spectroscopic fingerprints of such quantum confinement have been demonstrated widely, the consequences for carrier dynamics are at present less clear, particularly on ultrafast timescales. This is important for tailoring, probing, and understanding spin and electron dynamics in layered and two-dimensional materials even in cases where the desired bandgap engineering has been achieved. Here we show by means of core-hole clock spectroscopy that SnS2 exhibits spin-dependent attosecond charge delocalization times (τ deloc) for carriers confined within a layer, τ deloc < 400 as, whereas interlayer charge delocalization is dynamically quenched in excess of a factor of 10, τ deloc > 2.7 fs. These layer decoupling dynamics are a direct consequence of strongly anisotropic screening established within attoseconds, and demonstrate that important two-dimensional characteristics are also present in bulk crystals of van der Waals-layered materials, at least on ultrafast timescales.
AB - Strong quantum confinement effects lead to striking new physics in two-dimensional materials such as graphene or transition metal dichalcogenides. While spectroscopic fingerprints of such quantum confinement have been demonstrated widely, the consequences for carrier dynamics are at present less clear, particularly on ultrafast timescales. This is important for tailoring, probing, and understanding spin and electron dynamics in layered and two-dimensional materials even in cases where the desired bandgap engineering has been achieved. Here we show by means of core-hole clock spectroscopy that SnS2 exhibits spin-dependent attosecond charge delocalization times (τ deloc) for carriers confined within a layer, τ deloc < 400 as, whereas interlayer charge delocalization is dynamically quenched in excess of a factor of 10, τ deloc > 2.7 fs. These layer decoupling dynamics are a direct consequence of strongly anisotropic screening established within attoseconds, and demonstrate that important two-dimensional characteristics are also present in bulk crystals of van der Waals-layered materials, at least on ultrafast timescales.
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U2 - 10.1038/s41467-017-01522-3
DO - 10.1038/s41467-017-01522-3
M3 - Article
C2 - 29118395
AN - SCOPUS:85033368536
VL - 8
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 1369
ER -