Abstract
We show that chiral (nearly) flat band superconductivity can develop and host novel Majorana fermions at a time-reversal pair of symmetry-protected three-band crossing points. Based on symmetry analysis, mean-field study, and superfluid stiffness calculation, we determine and analyze the irreducible pairing channels with flat band pairings in the low-energy spin-$1$ fermion theory. Flat band pairing can enhance superconductivity dramatically, where the critical temperature scales linearly in the interaction strength. While fully gapped flat band pairing states develop in the single-component pairing channels, we find chiral $\bar p\pm i\bar p$ flat band superconductivity in the multicomponent pairing channels. Three-dimensional itinerant Majorana fermions arise at the bulk nodal points, whereas Majorana arcs appear on the surface.
Highlights
Chiral superconductivity has attracted much attention of modern condensed matter research in the past decades [1,2]
Our analysis focuses on the channels with flat band pairings, which raise the critical temperatures to the linear scaling of interest
We identify the irreducible pairing channels based on a symmetry analysis, study the flat band pairing states that can arise in these channels
Summary
Chiral superconductivity has attracted much attention of modern condensed matter research in the past decades [1,2]. The true critical temperature of superconductivity is determined by the stronger fluctuation Tc = min{Tcpair, Tcphase}, with the linear scaling Tc ∼ V generally manifested Such dramatic enhancement has motivated an intensive search for flat band superconductivity in practical materials. Various 2D systems have been studied including surfaces of gapless topological materials [22], strained graphene [23], and graphene moiré heterostructures [29,30] Motivated by these mainstreams of modern condensed matter research, we consider a platform where chiral superconductivity may develop on the 3D flat bands.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
