Effect of the Rashba interaction on the tunneling time and Hartman effect in an 8-Pmmn borophene superlattice

Abstract

The spin-dependent group delay time and Hartman effect as well as the valley/spin polarization in an 8-Pmmn borophene superlattice under Rashba interaction are investigated theoretically, by using the stationary phase and the transfer matrix approaches. The group delay time depends on the spin degree of freedoms, and can be effectively controlled by changing the direction of superlattice, incident electron angle and Rashba strength. Both the valley and spin polarization reveal a strong dependence on the number of the superlattice barriers. Furthermore, group delay time oscillates as the width of the potential barriers increases, but in special conditions, the dependence on the width of the potential barriers will disappear. Interestingly, by increasing the angle of the direction of the superlattice the Hartman effect can be observed for most electron incidence angles. Our study show that, the 8-Pmmn borophene superlattice can be useful for future electronics and spintronics applications.