  The amplitude of ground state superconducting energy gap $\Delta(0)$ and
relative jump in electronic specific heat at the transition temperature,
$\Delta$$C$${/}$$\gamma$$T_c$, are primary fundamental parameters of any
superconductor. There are several well-established techniques to measure these
values for bulk samples. However, there is limited number of techniques which
can be applied to measure these parameters in atomically thin superconductors.
Here we proposed a new approach to extract $\Delta(0)$ and
$\Delta$$C$${/}$$\gamma$$T_c$ in atomically thin superconductors by utilizing
perpendicular, Bc2,perp(T) (when magnetic field is applied in perpendicular
direction to the film surface), and parallel, Bc2,||(T) (when magnetic field is
applied in parallel direction to the film surface), upper critical field data.
Deduced parameters for few layers thick Al, Sn, NbSe2, MoS2, magic angle
twisted trilayer graphene (MATTG), and WTe2 are well matched values expected
for strong- and moderately strong-coupled electron-phonon mediated
superconductors. Observed, in many atomically thin superconductors, an
enhancement of Bc2,||(0) above the Pauli-Clogston-Chandrasekhar limiting field
(i.e., magnetic field required to break the Cooper pair) is explained based on
the sample geometry, without an assumption that some exotic pairing mechanism,
for instance, Ising-type, is emergent in these materials.
