Multiple-qcurrent states in a multicomponent superconducting channel.

Area of Science:

• Condensed Matter Physics
• Superconductivity
• Materials Science

Background:

• Multicomponent superconductors exhibit diverse nonstandard phenomena, including broken-time reversal symmetry (BTRS) states, exotic Fulde-Ferrell-Larkin-Ovchinnikov phases, and topological defects.
• These phenomena arise from the complex interactions within multiple superconducting condensates.

Purpose of the Study:

• To identify and characterize novel inhomogeneous current states in two-component superconducting quasi-one-dimensional channels.
• To investigate the interplay between homogeneous and inhomogeneous current states under specific conditions.

Main Methods:

• Utilized the Ginzburg-Landau formalism to model a dirty two-band superconductor.
• Incorporated sizable impurity scattering treated within the Born approximation.
• Analyzed the behavior of Cooper pair condensates and their momenta.

Main Results:

• Introduced a novel 'multiple-q state' characterized by two interpenetrating Cooper pair condensates with different total momenta.
• Demonstrated that multiple-q states can induce transitions between homogeneous (BTRS and non-BTRS) and inhomogeneous states.
• Identified a saw-like dependence of the depairing current and bistable current states as hallmarks of the multiple-q state in thin wires.

Conclusions:

• The study extends the known phenomena in multicomponent superconductors by introducing the multiple-q state.
• This state reveals a complex interplay between homogeneous and inhomogeneous current states.
• The findings suggest potential for novel superconducting device functionalities based on bistable current states.