Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultra-fast Double Pulse All-Optical Re-switching of a Ferrimagnet   All-optical re-switching has been investigated in the half-metallic Heusler
ferrimagnet Mn2Ru0.9Ga, where Mn atoms occupy two inequivalent sites in the
XA-type structure. The effect of a second 200 fs 800 nm pump pulse that follows
a first pulse, when both are above the threshold for switching, is studied as a
function of t12, the time between them. The aims are to identify the physical
mechanisms involved and to determine the minimum time needed for re-switching.
The time trajectory of the switching process on a plot of sublattice angular
momentum, S4a vs S4c, is in three stages; When t < 0.1 ps, the sublattice
moments are rapidly disordered, but not destroyed, while conserving net angular
momentum via optical spin-wave excitations. This leads to transient parallel
alignment of the residual Mn spins in the first quadrant. The net angular
momentum associated with the majority sublattice then flips in about 2 ps, and
a fully-reversed ferrimagnetic state is then established via the spin-lattice
interaction, which allows re-switching provided t12 > 10 ps.

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The categories of this paper are: q-alg
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
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The categories of this paper are: cs
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The categories of this paper are: hep-th
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The categories of this paper are: bayes-an
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The categories of this paper are: math-ph
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin