Majorana corner modes in an s-wave second order topological superfluid

Area of Science:

• Condensed Matter Physics
• Topological Materials
• Superfluidity

Background:

• Conventional topological superfluids feature boundary states.
• Higher-order topological superfluids (order r > 1) exhibit Majorana excitations in dimensions n-r, not n-1.
• Previous proposals for Majorana excitations often require unconventional pairing symmetries.

Purpose of the Study:

• To propose a novel scheme for realizing higher-order topological superfluids.
• To demonstrate the emergence of Majorana corner modes in a second-order topological superfluid.
• To utilize conventional s-wave pairing for realizing these phenomena.

Main Methods:

• Theoretical proposal combining a topological insulator, an in-plane Zeeman field, and s-wave pairing.
• Analysis based on low-energy theory of edge states.
• Investigating the role of effective Dirac mass sign changes at corners.

Main Results:

• Successfully unveiled the emergence of Majorana corner modes.
• Demonstrated that s-wave pairing can support second-order topological superfluids.
• Identified the key ingredients and conditions for realizing these modes.

Conclusions:

• The proposed scheme offers a promising platform for experimental implementation of 2D second-order topological superfluids.
• This work expands the possibilities for generating and studying Majorana corner modes.
• Highlights the potential of s-wave pairing in higher-order topological phenomena.