Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Three-step Model of High Harmonic Generation using Complex Classical
  Trajectories   We present a new trajectory formulation of high harmonic generation that
treats classically allowed and classically forbidden processes within a single
dynamical framework. Complex trajectories orbit the nucleus, producing the
stationary Coulomb ground state. When the field is turned on, these complex
trajectories continue their motion in the field-dressed Coulomb potential and
therefore tunnel ionization, unbound evolution and recollision are described
within a single, seamless framework. The new formulation can bring mechanistic
understanding to a broad range of strong field physics effects.

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The categories of this paper are: atom-ph
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
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The categories of this paper are: supr-con
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The categories of this paper are: math-ph
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The categories of this paper are: solv-int
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The categories of this paper are: hep-lat