  Superconductivity has been one of the most fascinating quantum states of
matter for over several decades. Among the superconducting materials,
LaAlO3/SrTiO3 interface is of particularly interest since superconductivity
exists between two insulating materials, which provides it with various unique
applications compared with bulk superconductors and makes it a suitable
platform to study the quantum Hall effect, charge density wave,
superconductivity and magnetism in one device. Therefore, a lot of efforts have
been made to search new superconducting oxide interface states with higher
superconducting critical temperature (TC). Recently, a superconducting state
with TC ~ 2 K has been found at the interface between a ferromagnetic insulator
EuO and a band insulator (111)-KTaO3. Here, we report the experimental
investigation of the superconductor-metal quantum phase transition of the
EuO/KTaO3 interface. Around the transition, a divergence of the dynamical
critical exponent is observed, which supports the quantum Griffiths singularity
in the EuO/KTaO3 interface. The quantum Griffiths singularity could be
attributed to large rare superconducting regions and quenched disorders at the
interface. Our results could pave the way for studying the exotic
superconducting properties at the EuO/KTaO3 interface.
