0 33 p respectively alternatively the quantum wave interference layer units and a u03b4 layer can be made of quaternary compounds such as al x ga y in 1 x u2212 y p or al x ga y in 1 x u2212 y as selecting arbitrary composition ratio within the range of 0 u2266 x u2266 1 0 u2266 y u2266 1 and 0 u2266 x y u2266 1 as another alternative the quantum wave interference layer can be made of group iii v compound semiconductor group ii vi compound semiconductors si and ge and semiconductors of other hetero material the desirable compositions are as follows each combinations is represented by a composition of a layer having a wide band width a layer having a narrow band width a substrate and x and y are arbitrary values wherein 0 u2266 x u2266 1 and 0 u2266 y u2266 1 as long as they are not specified lt 1 gt al x in 1 u2212 x p ga y in 1 u2212 y p gaas lt 5 gt alas al x ga 1 x as gaas 0 8 u2266 x u2266 0 9 lt 6 gt inp ga x in 1 u2212 x as y p 1 u2212 y gaas lt 8 gt si sige x c y arbitrary material 0 1 u2266 x u2266 0 3 0 lt y u2266 0 1 lt 9 gt al x1 ga y1 in 1 x1 y1 n al x2 ga y2 in 1 u2212 x2 u2212.