Magnetic order on a topological insulator surface with warping and proximity-induced superconductivity

Abstract

We determine the nature of the magnetic order on the surface of a topological insulator (TI) which develops due to hexagonal warping and the resulting Fermi surface (FS) nesting in the presence of a repulsive Hubbard interaction. For this purpose we investigate the spin susceptibility and derive a Landau theory to compare the different accessible phases. For a nearly hexagonal FS and sufficiently strong interaction the magnetic ground state is formed by a skyrmion lattice, i.e., by a superposition of three helical spin density waves which preserves C${}_3$ symmetry. The magnetic ground state is topologically nontrivial with a nonzero skyrmion charge, which can be stabilized and controlled by an applied magnetic field. By bringing the TI in proximity to a conventional superconductor one can engineer a C${}_3$-symmetric topological superconductor. We explore the modification of the phase diagram as well as the mutual influence between the skyrmion structure and a multipolar distribution of supercurrents, which can provide information about the underlying skyrmion charge.

Main text: 15 pages and 11 figures; Appendix: 4 pages and 2 figures; v2: slight modifications and updated references

References in corpus (16)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Insulators with Inversion Symmetry
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• Topological Field Theory of Time-Reversal Invariant Insulators
• First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
• Electrically detected interferometry of Majorana fermions in a topological insulator
• Topology of crystalline insulators and superconductors
• On the $Z_2$ classification of Quantum Spin Hall Models
• Direct Measurement of the Out-of-Plane Spin Texture in the Dirac Cone Surface State of a Topological Insulator
• Flat Majorana bands in 2-d lattices with inhomogeneous magnetic fields: topology and stability
• Magneto-Josephson effects in junctions with Majorana bound states
• Spin Susceptibility and Helical Magnetic Orders at the Edges/Surfaces of Topological Insulators Due to Fermi Surface Nesting
• Density Waves Instability and a Skyrmion Lattice on the Surface of Strong Topological Insulators

Cited by in corpus (12)

• A moiré superlattice on the surface of a topological insulator
• Majorana modes in emergent-wire phases of helical and cycloidal magnet-superconductor hybrids
• Topological Superconductivity Induced by Magnetic Texture Crystals
• Designer Meron Lattice on the Surface of a Topological Insulator
• Magic angle conditions for twisted 3D topological insulators
• Magnetic skyrmion crystal at a topological insulator surface
• Scanning tunneling spectroscopy as a probe of multi-Q magnetic states of itinerant magnets
• Trapping Majorana Zero Modes in Vortices of Magnetic Texture Crystals Coupled to Nodal Superconductors
• Mechanisms for Magnetic Skyrmion Catalysis and Topological Superconductivity
• Anatomy of Spin and Current Generation from Magnetization Gradients in Topological Insulators and Rashba Metals
• Majorana bound states with chiral magnetic textures
• New mechanisms to engineer magnetic skyrmions and topological superconductors