Superconductor-insulator transition in two-dimensional indium-indium-oxide composite.

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Superconductor-to-insulator transitions (SIT) are fundamental phenomena in condensed matter physics.
• Understanding the role of magnetic fields and material structure is crucial for controlling these transitions.

Purpose of the Study:

• To investigate the magnetic-field-tuned superconductor-to-insulator transition (H-SIT) in a novel hybrid system.
• To explore the critical behavior and magnetoresistance properties of superconducting indium islands on an indium oxide thin film.

Main Methods:

• Fabrication of a hybrid system using superconducting indium islands on an indium oxide (InOx) thin film.
• Tuning InOx film conductivity via vacuum annealing to modify intergrain coupling.
• Measurement of magnetoresistance and critical behavior under varying magnetic fields.

Main Results:

• The hybrid system demonstrated a "giant" magnetoresistance above the H-SIT.
• Critical behavior mirrored that of uniform InOx films but at significantly lower magnetic fields.
• Evidence of duality between Cooper pairs and vortices was observed.

Conclusions:

• The hybrid system provides a unique platform for studying quantum criticality and nonequilibrium phenomena.
• The observed giant magnetoresistance highlights the potential for novel electronic applications.
• The study elucidates the interplay between superconductivity, insulating states, and magnetic fields.