tailieunhanh - Wave Propagation Part 6

Tham khảo tài liệu 'wave propagation part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | The Electrodynamic Properties of Structures with Thin Superconducting Film in Mixed State 167 great importance thin Kerr nonlinear dielectric produces the soliton-like pulses thin superconducting film gives the possibility of control negative index material slab reduces the pulse velocity providing large interaction of pulses with a flux-line lattice in superconductor. Fig. 14. Magnitude of the pulse velocity as function of external magnetic field. The parameters of the structure are t 40 nm n 10-8 N-s m2 jyo 109 A m2 20-1011 rad s a m b 0 02 m s 100 pm Es 103 v m a3 10-15 C-m V2 7. Conclusion In this chapter the propagation of electromagnetic waves in structures with thin high temperature superconducting film is investigated. The interaction of electromagnetic wave with thin superconductor in the mixed state is studied. It is shown that the presence of the moving magnetic vortex structure in superconductor can lead not only to attenuation but also to amplification of electromagnetic waves. The condition of amplification consists in equality of velocity of electromagnetic wave and the moving vortex structure. It is shown that the electromagnetic wave amplification takes place at the expense of energy of Abrikosov vortex lattice. The representation of thin superconducting film in the form of boundary condition has enabled us to understand the mechanism of electromagnetic wave interaction with moving vortex structure. This method allowed us to simplify the numerical calculation. In this study also the propagation of electromagnetic waves in periodic structures superconductor - dielectric is examined. The peculiarities of periodic structures with thin superconducting film in Larkin-Ovchinnikov state are revealed. The features of periodic structures superconductor - semiconductor are studied. The new pass bands and amplification bands are found. The possibility of the control of processes of attenuation and amplification is shown. The control can be realized by .