Dear Gang Chen,

From: GANG CHEN chggst@physics.ucsb.edu Date: Mon, 27 Aug 2007 18:20:07 -0700

Hi, all

The site operators for spin are defined as S+, S- and Sz in ALPS, in order to express Sy, we need to introduce "i".

Now I have a spin Hamiltonian, if I express it in terms of S+, S- and Sz, there will be "i" terms in the Hamiltonian. In such case, how do I specify each term or parameters?

<Use "I" (capital i) for unit imaginary, e.g.

<SITEOPERATOR name="Sy" site="x"> 1/(2*I)*(Splus(x)-Sminus(x)) </SITEOPERATOR>

Best, Synge Todo wistaria@comp-phys.org