Spin orbit induced anisotropic giant effective g factor and reduced effective mass in non-magnetic Sn1-,,Sr,,Te mixed crystal

The binary and ternary telluride systems containing europium as one of the magnetic components exhibit a higher effective g factor and much lower effective mass due to strong spin-orbit and s/p-f hybridized interaction mediated by the dopant impurity. In this communication, we have exploited the same for a ternary mixed crystal Sn1-xSrxTe, with strontium as the non-magnetic counterpart of europium. We have derived a functional equation within the framework of effective mass representation, accounting for both spin-orbit interaction and the presence of a magnetic field. In the context of k(->)& sdot;pi(->) model, at first, two MW (Mitchell-Wallis) band edge states are diagonalized properly, and subsequently, the off-band edge states are treated using perturbation up to the k(2) level. We derived the formulas for the effective g factor and effective mass by employing Green's function method, considering the presence of spin-orbit interaction, magnetic field, and Sr impurity and assuming band inversion model as applicable to Sn1-xSrxTe system. Finally, we conduct a comprehensive examination of the effective g factor, effective mass, and their respective anisotropies in Sn1-xSrxTe considering their dependence on carrier concentration and impurity levels at T=300K. We present extremely elevated effective g factor; g=2230, for Sn1-xSrxTe and g=2160, for p-Sn1-xSrxTe respectively with large anisotropies and correspondingly low effective mass m(c,v)=0.003m(0) around x=0.014 in the concentration range 0.01x10(19) cm(-3) to 0.1x10(19) cm(-3). Irrespective of the unsaturated electronic shell of Sr, the existence of strong spin-orbit interaction refers to the strong coupling of band edge states across the band minima triggered by substitutional impurity. The occurrence of a substantial effective g factor and low effective mass is unique in such non-magnetic Sn1-xSrxTe mixed crystal ever reported.

Automated summary

The binary and ternary telluride systems containing europium as one of the magnetic components exhibit a higher effective g factor and much lower effective mass due to spin-orbit interaction and s/p-f hybridized interaction. In this study, we investigated the ternary mixed crystal Sn1-xSrxTe, with strontium as the non-magnetic counterpart of europium, and derived functional equations and expressions for the effective g factor and effective mass. The results show that Sn1-xSrxTe has extremely elevated effective g factors and low effective mass, suggesting strong spin-orbit interaction and band edge coupling induced by substitutional impurity.