h2、0 H ∑n+27g∑8( 2MR480 a metastable state at L=N It carries a persistent current (Leggett, Rev. Mod. Phys. 73, (2001) E: in unit of h/2mR L: in unit of h See also, F. Bloch, Phys. Rev. A, 7 (1973) Rotating frame with Q2=l L E=E-QL N=10g=1(Leggett, Rev. Mod. Phys. 73,(2001) See also, F. Bloch, Phys. Rev. A,7 (1973)) N=10 g=1 Rotating frame with  = 1 E E L  = −  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