  In contrast to conventional superconducting (SC) materials, superconductivity
in high-temperature superconductors (HTCs) usually emerges in the presence of
other fluctuating orders with similar or higher energy scales, thus instigating
debates over their relevance for the SC pairing mechanism. In iron-based
superconductors (IBSCs), local orbital fluctuations have been proposed to be
directly responsible for the structural phase transition and closely related to
the observed giant magnetic anisotropy and electronic nematicity. However,
whether superconductivity can emerge from, or even coexist with orbital
fluctuations, remains unclear. Here we report the angle-resolved photoemission
spectroscopy (ARPES) observation of the lifting of symmetry-protected band
degeneracy, and consequently the breakdown of local tetragonal symmetry in the
SC state of Li(Fe1-xCox)As. Supported by theoretical simulations, we analyse
the doping and temperature dependences of this band-splitting and demonstrate
an intimate connection between ferro-orbital correlations and
superconductivity.

Superconductivity;Strongly Correlated Electrons