Abstract
Lattice geometry continues providing exotic topological phases in condensed matter physics. Exciting recent examples are the higher-order topological phases, manifesting via localized lower-dimensional boundary states. Moreover, flat electronic bands with a non-trivial topology arise in various lattices and can hold a finite superfluid density, bounded by the Chern number C. Here we consider attractive interaction in the dice lattice that hosts flat bands with C = ± 2 and show that the induced superconducting state exhibits a second-order topological phase with mixed singlet-triplet pairing. The second-order nature of the topological superconducting phase is revealed by the zero-energy Majorana bound states at the lattice corners. Hence, the topology of the normal state dictates the nature of the Majorana localization. These findings suggest that flat bands with a higher Chern number provide feasible platforms for inducing higher-order topological superconductivity.
Original language | English |
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Article number | 240 |
Journal | Communications Physics |
Volume | 6 |
Issue number | 1 |
DOIs | |
State | Published - Dec 2023 |
Funding
This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. N.M. acknowledges the National Supercomputing Mission for providing computing resources of Param Ganga at the Indian Institute of Technology Roorkee, which is implemented by C-DAC and supported by the Ministry of Electronics and Information Technology and Department of Science and Technology, Government of India.