Ground State of S=1 Heisenberg Ladders
Access this Article
Search this Article
The ground state of S = 1 antiferromagnetic Heisenberg (AFH) two-leg ladder has been shown to be gapful, in a whole range from the weak rung coupling limit to the strong rung coupling limit. The well-known valence-bond solid (VBS) picture for single AFH chains does not hold for this disordered ground state. We generalize the VBS picture to the plaquette-singlet solid (PSS) one to obtain a good description of the S = 1 ladder. The validity of the PSS picture for this system is also supported by the finiteness of a newly-introduced hidden order parameter analogous to the string order parameter. We observe that there is also no critical point in the ground state of ladders with in-phase leg-bond alternation.
- Progress of Theoretical Physics
Progress of Theoretical Physics (145), 221-224, 2002-06-28
Progress of Theoretical Physics