The Angular momentum aspect of shift in FQHE
  The angular momentum of the Hall particles acquiring Berry phases from quantization,is the very source of unifying the physics of IQHE and FQHE. The origin of {\it Shift} quantum number lies in the change of angular momentum of the Hall particles from higher to lower Landau level. Here the non-vanishing effect of {\it Shift} in 2D has been evaluated in the framework of $Z_p$ spin system and in view of these, Ising model and XY model are studied. 
Dipti Banerjee