  Recent experiments on Landau-Zener interference in multilevel superconducting
flux qubits revealed various interesting characteristics, which have been
studied theoretically in our recent work by simply using rate equation method
[PRB 79, 094529, (2009)]. In this note we extend this method to the same system
but with larger driving amplitude and higher driving frequency. The results
show various anomalous characteristics, some of which have been observed in a
recent work.
