Superconducting (SC) gap of elemental yttrium under extreme pressure conditions was directly probed via the point-contact spectroscopy (PCS) in a diamond anvil cell. Strong enhancement in the differential conductance near the zero-biased voltage is observed owing to Andreev reflection, a hallmark of superconductivity. Taken together with the large initial slope of the upper critical field, the large SC gap-to-Tc ratio suggests that Y belongs to a family of the strongly coupled BCS superconductors.
- Zi-Yu Cao
- Harim Jang
- Tuson Park
