Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magic gap ratio for optimally robust superconductivity and its
  implications for high-Tc   The cold atomic Fermi gas has become the essential paradigm for understanding
the crossover between the weak coupling Bardeen-Schrieffer-Cooper (BCS) and
strong coupling Bose-Einstein Condensation (BEC) regimes of paired fermion
condensates. On tuning the pairing interactions through the crossover, a
superfluid becomes optimally robust between the BCS and BEC regimes at what is
referred to as the unitary point, giving rise to a maximally peaked phase
transition anomaly in the specific heat. We find here, by tracing the jump
$\Delta\gamma$ in the electronic specific heat coefficient $\gamma$ at the
transition temperature $T_{\rm c}$ as a function of the gap ratio
$2\Delta/k_{\rm B}T_{\rm c}$, that a similar thermodynamic signature occurs in
the high-$T_{\rm c}$ superconducting cuprates. On taking $\Delta$ as the
pairing gap in a cold atomic Fermi gas and as the antinodal pseudogap energy in
the cuprates, we find $\Delta\gamma$ to be asymmetrically peaked at the same
value of $2\Delta/k_{\rm B}T_{\rm c}\approx$ 6.5. Its observation in the
cuprates and coincidence with a normal state maximum in $\gamma$ provides a
previously overlooked thermodynamic signature of an optimally robust condensate
at the BCS-BEC crossover.

9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
2
The categories of this paper are: math