If B/Bfocus is an integer, a fraction of order (1/kFL)1/3 of the N edge states interfere constructively at the collector. Because of the 1/3 power, this is a substantial fraction even for the large kFL ~ 102 of the experiment. The resulting mode interference oscillations with Bfocusperiodicity can become much larger than the classical focusing peaks. This has been shown in Refs.347 and80, where the transmission probability Ti→c was calculated in the WKB approximation with neglect of the finite width of the injector and detector. From Eq. (3.26) the focusing spectrum is then obtained in the form