Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantifying Ultrafast Three-Dimensional Transport Using
  Interferometrically Enhanced Pump-Probe Microscopy   We present a novel microscopic technique to access local transient optical
constants and carrier motion in thin-film materials in three dimensions, with
sub-10 nm spatial precision and sub-15 fs temporal resolution. Our experimental
scheme is based on imaging a traditionally defocussed plane in an
interferometrically enhanced femtosecond pump-probe microscope, combining the
amplitude and phase contrast between the perturbed and unperturbed probe due to
the local photoinduced complex refractive index change. We find that our
experimental approach is well described by a simple optical model based on a
radially averaged Gaussian photoexcitation approximation, which we benchmark
using finite-difference time-domain calculations. Measurements on the organic
semiconductor pentacene reveal an unexpected sub-1 ps out-of-plane motion of
the correlated triplet-triplet exciton. Our approach is applicable to thin film
materials in any pump-probe experiment, and holds promise for quantitative
studies of three-dimensional transport in semiconductors, especially relevant
to next-generation functional materials.

8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
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The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ