Super-Klein tunneling of massive pseudospin-one particles

The transmission properties of massive particles with pseudospin-one through homogeneous and heterogeneous junctions are studied from an effective spin-orbit Hamiltonian. The addition of a mass term in the Hamiltonian creates an energy band gap with a flat band inside the gap. There are three possible scenarios for the location of the flat band: at the top of the valence band, at the bottom of the conduction band, and at the center of the energy band gap. We have studied how the position of the flat band affects the transmission through a general type of junction. We found that omnidirectional perfect transmission, called super-Klein tunneling, occurs even for massive particles with specific symmetrical conditions in the junction. In all other cases, an angular independent transmission is obtained, which can be considered as an attenuated super-Klein tunnelling. These effects emerge when the junction operates as a Veselago lens under the generalized focusing condition. Furthermore, we found that Klein tunneling is restored in the massless limit. The present findings may have important implications in the development of electronic devices based on quantum optics with massive pseudospin-one particles.