Inverse Proximity Effect and Unconventional Superconductivity in the Pb/CrTe Hybrid Thin Films

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity

Background:

• Superconductor/ferromagnet hybrid thin films exhibit exotic phenomena like triplet pairing and the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state.
• Understanding interfacial interactions is crucial for novel electronic applications.

Purpose of the Study:

• To systematically investigate the properties of two-dimensional Pb/CrTe superconductor/ferromagnet hybrid thin films.
• To explore the emergence of unconventional superconductivity and FFLO-like states.

Main Methods:

• Scanning tunneling microscopy (STM) for atomic-level surface analysis.
• Transport measurements to probe superconducting properties.
• Systematic variation of ferromagnetic layer thickness.

Main Results:

• Observed a pronounced inverse proximity effect, leading to an unconventional superconducting gap structure.
• Superconducting transition temperature reduced by over 50%; upper critical field suppressed by over an order of magnitude.
• Observed oscillations in superconducting transition temperature with ferromagnetic layer thickness, indicating FFLO-like states.
• Re-entrant superconductivity emerged under an applied magnetic field.

Conclusions:

• Interfacial interactions in atomically thin superconductor/ferromagnet hybrids significantly impact superconducting properties.
• Evidence for FFLO-like states and re-entrant superconductivity was found, offering new avenues for research.
• These findings provide critical insights into unconventional superconductivity in hybrid thin films.