Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Structure of eigenstates and quench dynamics at an excited state quantum
  phase transition   We study the structure of the eigenstates and the dynamics of a system that
undergoes an excited state quantum phase transition (ESQPT). The analysis is
performed for two-level pairing models characterized by a U(n+1) algebraic
structure. They exhibit a second order phase transition between two limiting
dynamical symmetries represented by the U(n) and SO(n+1) subalgebras. They are,
or can be mapped onto, models of interacting bosons. We show that the
eigenstates with energies very close to the ESQPT critical point, E_{ESQPT},
are highly localized in the U(n)-basis. Consequently, the dynamics of a system
initially prepared in a U(n)-basis vector with energy close to E_{ESQPT} may be
extremely slow. Signatures of an ESQPT can therefore be found in the structures
of the eigenstates and in the speed of the system evolution after a sudden
quench. Our findings can be tested experimentally with trapped ions.

15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat