Longitudinal polar modes generate a macroscopic electric field in piezoelectric crystals and cause an additional mechanism of Raman scattering. The classical theory holds that transverse polar modes cannot produce suc...Longitudinal polar modes generate a macroscopic electric field in piezoelectric crystals and cause an additional mechanism of Raman scattering. The classical theory holds that transverse polar modes cannot produce such an additional mechanism. Our quantum theory shows that there is an additional Raman scattering mechanism arising from the electro-optic effect of transverse polar modes.展开更多
By using the simple decoupling approximation to Fermi-type Green＇s function for the transverse Ising model under pseudospin theory, we systemically study the influence of different exchange interactions （transverse ...By using the simple decoupling approximation to Fermi-type Green＇s function for the transverse Ising model under pseudospin theory, we systemically study the influence of different exchange interactions （transverse fields） of the two distinct materials on the polarization and Curie temperature of finite alternating superlattice. Meanwhile, we analyze the effect of the whole parameters of the top surface, present their influence on the polarization of each layer （including the mean polarization of the whole ferroeleetric superlattiee） and on the Curie temperature. The results show the ratio of the exchange interactions （the transverse fields）, which are of the two alternating materials have deeply impact on the polarization and Curie temperature of the supperlattice. Moreover, the top surface also has great influence on the whole ferroelectric superlattice.展开更多
文摘Longitudinal polar modes generate a macroscopic electric field in piezoelectric crystals and cause an additional mechanism of Raman scattering. The classical theory holds that transverse polar modes cannot produce such an additional mechanism. Our quantum theory shows that there is an additional Raman scattering mechanism arising from the electro-optic effect of transverse polar modes.
文摘By using the simple decoupling approximation to Fermi-type Green＇s function for the transverse Ising model under pseudospin theory, we systemically study the influence of different exchange interactions （transverse fields） of the two distinct materials on the polarization and Curie temperature of finite alternating superlattice. Meanwhile, we analyze the effect of the whole parameters of the top surface, present their influence on the polarization of each layer （including the mean polarization of the whole ferroeleetric superlattiee） and on the Curie temperature. The results show the ratio of the exchange interactions （the transverse fields）, which are of the two alternating materials have deeply impact on the polarization and Curie temperature of the supperlattice. Moreover, the top surface also has great influence on the whole ferroelectric superlattice.
