h2、0 H ∑n+27g∑8( 2MR480 a metastable state at l=n It carries a persistent current E: in unit of h/2mR L: in unit of h L N=10g=1N=10 g=1 A metastable state at L=N, It carries a persistent current. 2 2 2 2 1 2 ( ) 2 N N i j i i j i H g MR = = − + − 2 2 E mR L : / 2 , : in unit of in unit of