Majorana zero modes in Y-shape interacting Kitaev wires

Motivated by recent experimental advancements in minimal Kitaev chains using quantum dots, this paper investigates Majorana zero modes (MZMs) in Y-shape Kitaev wires. The study analytically solves associated Kitaev models at the sweet spot (t⊥ = Δ), deriving the exact form of MZM wave functions. Exotic multi-site MZMs near the junction center, on nearby edge sites of each leg, are observed. The stability of local and multi-site MZMs under Coulomb repulsion is examined using density matrix renormalization group theory. Local density-of-states calculations demonstrate that multi-site MZMs are as topologically protected as single-site MZMs, both with Coulomb repulsion and away from the sweet spot.

Bradraj Pandey, Nitin Kaushal, Gonzalo Alvarez, Elbio Dagotto