(color online) The contour plot of the transmission probability as a function of the incident angle and incident energy for the parallel alignment with a fixed barrier width w = 0.5, distance d = 2, and magnetic field B = 1, (a) , ; for panels (b)–(f), (b) , ; (c) , ; (d) , ; (e) , ; (f) the same as panel (b) but for B = 4. The magnetic unit , the energy unit is , and the length unit is . The number of FM stripes is N = 40.