Random matrix theory predicts characteristic distributions for the transmission amplitude T in dependence of the number of attached wave guides, and of time-reversal symmetry as well [1,2]. In quantum dots the predictions could be verified only qualitatively [3,4]. In the present experiment the transmission of microwave billiards was measured with and without [5] reflection symmetry for different numbers of channels. Time-reversal symmetry was broken via introduced ferrite cylinders. The obtained transmission intensity distributions are compared with predictions from random matrix theory. Because of the strong absorption caused by the ferrites, the existing statistical scattering theories had to be modified by incorporating a number of additional absorbing scattering channels. A better characteristic for the systems can be obtained from the distribution of dT/dE.
References
[1] H.U. Baranger and P.M. Mello, Phys. Rev. B 54 (1996) R14 297
[2] C. Beenakker, Rev. Mod. Phys. 69 (1997) 731
[3] A. Huibers et al., Phys. Rev. Lett. 81 (1998) 1917
[4] S.F. Godijn et al., Phys. Rev. Lett. 82 (1999) 2927
[5] H. Schanze et al., Phys. Rev. E 64 (2001) 065201(R)