  Utilizing an exactly sign-problem-free quantum Monte Carlo method, we explore
the influence of long-range Coulomb interaction on the superfluid transition
temperature of bipolarons in two dimensions. The model studied here is the bond
Su-Schrieffer-Heeger model with phonon-modulated electron hopping. Previously,
in the absence of long-range Coulomb interaction, this model demonstrated the
emergence of small-size, light-mass bipolarons that undergo a superfluid
transition at high values of the transition temperature $T_c$ [Physical Review
X 13, 011010, (2023)]. Our findings indicate that even with the inclusion of
long-range Coulomb interaction, $T_c$ remains substantially high, even in the
deep adiabatic regime where the phonon frequency is $\omega/t = 0.5$ and the
Coulomb interaction $V = U/10$. This result suggests a physical mechanism for
superconductivity in the low-density regime, which could hold relevance for
ongoing experiments on dilute superconductors.
