H G bra 3(ka 4G da H G d2 3(ka a2 T 0= (k 3Ta da2 4G 3Ta da2 4G a2y 9r2 a24(21:A a4)y=0 There is a tunneling for k= 1 2021/2/5 Zhang De-Hai2021/2/5 Zhang De-Hai 7