Helical Hinge Majorana Modes in Iron-Based Superconductors.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Physics

Background:

• Iron-based superconductors like FeTe_{1-x}Se_{x} exhibit complex electronic properties.
• Topological superconductivity and Majorana zero modes are of significant theoretical and experimental interest.
• Previous research focused on Majorana modes localized at vortices.

Purpose of the Study:

• To construct a minimal model for iron-based superconductors exhibiting band inversion.
• To investigate the intrinsic existence of Majorana modes in these systems.
• To explore the potential for higher-order topological superconductivity.

Main Methods:

• Development of an explicit minimal model for iron-based superconductors.
• Analysis of band inversion at the Z point and s_{±} pairing.
• Theoretical investigation of Majorana modes in the absence of vortices.

Main Results:

• The model intrinsically supports 1D helical Majorana modes localized at the hinges.
• These hinge modes suggest a realization of higher-order topological superconductivity.
• A general theory for these hinge modes, including their stability and experimental signatures, was developed.

Conclusions:

• Iron-based superconductors can host intrinsic hinge Majorana modes, offering a new avenue for topological quantum phenomena.
• This finding provides a viable platform for observing higher-order topological superconductivity.
• Experimental observation of these hinge Majorana modes in iron-based topological superconductors is indicated as possible.