Spin separation and filtering assisted by topological corner states in the Kekulé lattice

Abstract

Higher-order topological corner states have been realized in two-dimensional Kekulé lattice, which can be further coupled with spin polarization through the implementation of local magnetization. In this work, we numerically investigate the spin-dependent transport properties assisted by topological corner states in the Kekulé lattice. By applying local magnetization and electric potential, the topological corner states are spin polarized with opposite spins localized at different corners, thereby demonstrating a spin-corner state locking mechanism. Transport characteristics, including transmission, local density of states, and local current density, are calculated for a two-terminal setup consisting of a diamond-shaped Kekulé lattice connected to two leads. When opposite local magnetization is applied to the corners, spin-up and spin-down electrons are perfectly separated, forming two spin-polarized conducting channels and leading to spin spatial separation. In the presence of identical local magnetization on both corners and an electric potential at one corner, the spin-polarized corner states can facilitate selective filtering of different spins and generate spin-polarized currents by tuning the energy. Furthermore, spin-resolved transmission diagrams as functions of both the Fermi energy and electric potential are presented, illustrating the global distribution of spin filtering through topological corner states.

References in corpus (13)

• $(d-2)$-dimensional edge states of rotation symmetry protected topological states
• Higher-order topological insulators and semimetals on the breathing Kagome and pyrochlore lattices
• Direct observation of corner states in second-order topological photonic crystal slabs
• Electron fractionalization in two-dimensional graphenelike structures
• Photonic crystal nanocavity based on a topological corner state
• Pseudospins and topological effects of phonons in a Kekule lattice
• Evidence for Higher order topology in Bi and Bi${}_{0.92}$Sb${}_{0.08}$
• Multi-orbital model reveals second-order topological insulator in 1H-transition metal dichalcogenide
• Anti-chiral edge states and hinge states based on the Haldane model
• Partial local density of states from scanning gate microscopy
• Transport Induced Dimer State from Topological Corner States
• Transport features of topological corner states in honeycomb lattice with multihollow structure
• Bulk-boundary-transport correspondence of the second-order topological insulators