Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Table-top Nonlinear Extreme Ultraviolet Spectroscopy   The lack of available table-top extreme ultraviolet (XUV) sources with high
enough fluxes and coherence properties have limited the availability of
nonlinear XUV and x-ray spectroscopies to free electron lasers (FEL). Here, we
demonstrate second harmonic generation (SHG) on a table-top XUV source for the
first time by observing SHG at the Ti M2,3-edge with a high harmonic seeded
soft x-ray laser (HHG-SXRL) [1,2]. Further, this experiment represents the
first SHG experiment in the XUV. First-principles electronic structure
calculations are used to confirm the surface specificity and resonant
enhancement of the SHG signal. The realization of XUV-SHG on a table-top source
with femtosecond temporal resolution opens up tremendous opportunities for the
study of element-specific dynamics in multi-component systems where surface,
interfacial, and bulk-phase asymmetries play a driving role in smaller-scale
labs as opposed to FELs.

23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs