Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrafast coupled charge and spin dynamics in strongly correlated NiO   Charge excitations across an electronic band gap play an important role in
opto-electronics and light harvesting. In contrast to conventional
semiconductors, studies of above-band-gap photoexcitations in strongly
correlated materials are still in their infancy. Here we reveal the ultrafast
dynamics controlled by Hund's physics in strongly correlated photo-excited NiO.
By combining time-resolved two-photon photoemission experiments with
state-of-the-art numerical calculations, an ultrafast ($\lesssim$ 10\,fs)
relaxation due to Hund excitations and related photo-induced in-gap states are
identified. Remarkably, the weight of these in-gap states displays long-lived
coherent THz oscillations up to 2\,ps at low temperature. The frequency of
these oscillations corresponds to the strength of the antiferromagnetic
superexchange interaction in NiO and their lifetime vanishes as the N\'eel
temperature is approached. Numerical simulations of a two-band $t$-$J$ model
reveal that the THz oscillations originate from the interplay between local
many-body excitations and long-range antiferromagnetic order.

32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio