With ever-increasing operating frequencies and complicated artificial structures, loss effects become more and more important in applications of metamaterials. Based on circuit theory and transmission line principle, ...With ever-increasing operating frequencies and complicated artificial structures, loss effects become more and more important in applications of metamaterials. Based on circuit theory and transmission line principle, the design equations for effective electromagnetic (EM) parameters (attenuation constant α, phase constant β, characteristic impedance Z0) of general active and passive metamaterial are compared and derived from the equivalent lumped circuit parameters (R, G, LL, CL, LR, CR). To verify the design equations, theα, βand Z0 indifferent cases, including balanced, unbalanced, lossless, passive and active, are shown by numerical simulations. The results show that using the active method can diminish the loss effects. Meantime, it also has influence on phase constant and real part of characteristic impedance.展开更多
We investigate the effect of van der Waals interactions and dipole-dipole interactions on collisional loss rate coefficients of Cs Rydberg nP states, and in detail analyze the variation of collisional loss coefficient...We investigate the effect of van der Waals interactions and dipole-dipole interactions on collisional loss rate coefficients of Cs Rydberg nP states, and in detail analyze the variation of collisional loss coefficients under the initial Rydberg atomic velocity and van der Waals interactions. We obtain the total collisional loss coefficients for different nP states, and provide the possible ionization mechanism for the results of experimental observation using our analysis model.展开更多
文摘With ever-increasing operating frequencies and complicated artificial structures, loss effects become more and more important in applications of metamaterials. Based on circuit theory and transmission line principle, the design equations for effective electromagnetic (EM) parameters (attenuation constant α, phase constant β, characteristic impedance Z0) of general active and passive metamaterial are compared and derived from the equivalent lumped circuit parameters (R, G, LL, CL, LR, CR). To verify the design equations, theα, βand Z0 indifferent cases, including balanced, unbalanced, lossless, passive and active, are shown by numerical simulations. The results show that using the active method can diminish the loss effects. Meantime, it also has influence on phase constant and real part of characteristic impedance.
文摘We investigate the effect of van der Waals interactions and dipole-dipole interactions on collisional loss rate coefficients of Cs Rydberg nP states, and in detail analyze the variation of collisional loss coefficients under the initial Rydberg atomic velocity and van der Waals interactions. We obtain the total collisional loss coefficients for different nP states, and provide the possible ionization mechanism for the results of experimental observation using our analysis model.
