Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum mechanics and speed limit of ultrafast local control in spin
  chains   We study optimization of fidelity for ultrafast transformation of a spin
chain via external control of a local exchange coupling. We show that
infidelity of such a process can be dramatically decreased by choosing a proper
control profile in nonadiabatic time domain, predict main features of this
profile analytically, corroborate them numerically with a gradient search
algorithm, and discuss the corresponding quantum speed limit. For ultrafast
transformations, the qualitative features of the obtained optimal control are
system-independent. Moreover, the main restrictions on its shape do not depend
on the transformation time and remain valid up to the adiabatic limit. Our
results can be applied to control a broad variety of quantum systems.

28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an