Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Detecting a preformed pair phase: The response to a pairing forcing
  field   The normal state of strongly coupled superconductors is characterized by the
presence of "preformed" Cooper pairs well above the superconducting critical
temperature. In this regime, the electrons are paired, but they lack the phase
coherence necessary for superconductivity. The existence of preformed pairs
implies the existence of a characteristic energy scale associated to a
pseudogap. Preformed pairs are often invoked to interpret systems where some
signatures of pairing are present without actual superconductivity, but an
unambiguous theoretical characterization of a preformed-pair system is still
lacking. To fill this gap, we consider the response to an external pairing
field of an attractive Hubbard model, which hosts one of the cleanest
realizations of a preformed pair phase, and a repulsive model where s-wave
superconductivity can not be realized. Using dynamical mean-field theory to
study this response, we identify the characteristic features which distinguish
the reaction of a preformed pair state from a normal metal without any
precursor of pairing. The theoretical detection of preformed pairs is
associated with the behavior of the second derivative of the order parameter
with respect to the external field, as confirmed by analytic calculations in
limiting cases. Our findings provide a solid testbed for the interpretation of
state-of-the-art calculations for the normal state of the doped Hubbard model
in terms of d-wave preformed pairs and, in perspective, of non-equilibrium
experiments in high-temperature superconductors.

29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org