Giant shot noise in superconductor/ferromagnet junctions with orbital-symmetry- controlled spin-orbit coupling

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Phenomena

Background:

• Superconducting proximity effects typically involve two superconductors influencing each other.
• Orbital symmetries and spin-orbit coupling play crucial roles in exotic electronic phenomena.
• Understanding interfacial effects is key to designing novel quantum devices.

Purpose of the Study:

• To investigate shot noise in superconductor/insulator/ferromagnet (V/MgO/Fe) junctions.
• To explore the implications of orbital-symmetry-controlled proximity effects.
• To understand the emergence of unconventional superconductivity at interfaces.

Main Methods:

• Measurement of shot noise in V/MgO/Fe junctions.
• Analysis of charge quantization effects.
• Characterization of superconducting proximity effects at interfaces.

Main Results:

• Observed a giant, unexpected increase in shot noise, orders of magnitude larger than predicted.
• Discovered a novel superconducting proximity effect driven by orbital symmetries and spin-orbit coupling.
• Identified the formation of a distinct spin-triplet superconducting region due to broken inversion symmetry and interfacial spin-orbit coupling.

Conclusions:

• The study reveals significant, unexplored consequences of orbital-symmetry-controlled proximity effects.
• Enhanced shot noise can occur even with a single superconductor, challenging existing paradigms.
• This discovery necessitates a re-evaluation of spin-orbit coupling and proximity effects in material transformations.