A quantum critical point in the transverse field of Mn12 system
  Using exact diagonalization method,we studied the ground state of the anisotropic molecular magnets and find a critical point in the transverse field,which may divide the quantum tunneling region into two different parts. Possible ways to observe and take advantage of this point by varying the transverse field are suggested. 
Yongjin Jiang, Haijin Li and Ruibao Tao