Tuning the Andreev reflection in a multi-terminal device with kink states

Abstract

At the domain wall between two regions with opposite Chern numbers, there are one-dimensional chiral states, which are called kink states. These kink states are robust under lattice deformations. We design a multi-terminal device with kink states and study the local Andreev reflection and the crossed Andreev reflection. In a three-terminal device, the local Andreev reflection can be suppressed completely for either ɛ 0 = 0 . 01 t and V 0 = 0 . 1 t or ɛ 0 = − 0 . 0 . 01 t and V 0 = − 0 . 1 t , where ɛ 0 is the on-site energy of the graphene terminals and V 0 is the stagger energy of the center region. The coefficient of the crossed Andreev reflection can reach 1 in a four-terminal device. Besides adjusting the phase difference between superconductors, the local Andreev reflection and the crossed Andreev reflection can be controlled by changing the on-site energy and the stagger energy in a four-terminal device. Our results may lead to new possibilities for quantum devices. • We find that kink states at the domain wall are robust under lattice deformations. • Andreev reflection can be controlled by adjusting the on-site and stagger energy. • The mechanism of electron transport in the device with kink states is explained.