Nonlocal Unitary Transformations onS=1 Antiferromagnetic Spin Chains

We propose nonlocal unitary transformations on S =1 antiferromagnetic chains in a simple operator form. This is a generalization of the transformation recently introduced by Kennedy and Tasaki to clarify the hidden symmetry in the Haldane phase. The three operators ( T i α ≡ i S i α e i πS i β ) a p p e a r i n g i n t h e s e t r a n s f o r m a t i o n s a r e e x a m i n e d a n d s o m e s i m p l e a l g e b r a i c r e l a t i o n s a r e s h o w n t o h o l d a m o n g T_i^α a n d S_i^α. I t i s a l s o s h o w n t h a t t h r e e d i f f e r e n t f o r m s o f t r a n s f o r m e d H a m i l t o n i a n s a r e t r a n s f o r m e d i n t o e a c h o t h e r b y local u n i t a r y t r a n s f o r m a t i o n s .