Study of the properties of strong-coupling magnetopolaron in quantum disks induced by the Rashba spin-orbit interaction

Abstract

On the basis of Lee-Low-Pines unitary transformation, the properties of strong-coupling magnetopolarons in quantum disks (QDs) induced by the Rashba spin-orbit interaction are studied using the Tokuda improved linearly combined operator method. Results show that the state properties of magnetopolarons are closely linked with the sign of the interaction energy Eint, and the Eint of magnetopolarons changes with the transverse confinement strength 0, the cyclotron frequency of the external magnetic field c, the electron-LO phonon coupling strength , and the thickness L of QDs. The average number N of phonons increases with increasing c, 0 and , but the oscillation decreases with increasing thickness L of QDs. The effective mass m0* of magnetopolarons splits into two (m+*, m-*), induced by the Rashba spin-orbit interaction, and the values of them increase with increasing c, 0 and , but the oscillation decreases with increasing thickness L of QDs. For the ground state of magnetopolarons in QDs, the electron-LO phonon interaction plays a significant role, meanwhile, the Rashba spin-orbit coupling effect cannot be ignored. Only for the lower volocity of the electrons, can the polaron effect and the Rashba spin-orbit interaction effect on the magnetopolaron be obvious.

Properties of strong-coupling magneto-bipolaron qubit in quantum dot under magnetic field

“…As the electron-phonon coupling constant of the I-VII semiconductors is an order of magnitude larger than that of the III-V semiconductors, and the electron-phonon interaction in the quantum dot made of such materials becomes even stronger due to the lower dimensionality (usually the electron-phonon coupling strength is greater than 6), the bound state of bipolaron can be formed by the interaction between two identical electrons through the phonon field. [19][20][21] In the study of bipolaron in magnetic field, one of the authors [21] first proposed the concept of magnetobipolaron. It is no doubt that, for the quantum dot made of I-VII semiconductor materials, it is impossible and not necessary to restrain the bipolaron formation, and the study of the bipolaron qubit has more practical significance and potential in application than the study of the polaron qubit alone.…”