Bond operator method of dimerized ferrimagnetic spin chain.

We use bond operator method to study the dimerized ferrimagnetic spin chain. With the dimerization parameter g from 1 to 0, the model describes the system from normal ferrimagnetic state to dimer state. From the energy spectrums, the system energy is changed from ferrimagnetic spectrum to large energy gap at bond state. At finite temperature, the uniform susceptibility, internal energy and specific heat are calculated respectively with different dimerization parameters g . These results qualitatively agree with the numerical results of other methods quite well. [ABSTRACT FROM AUTHOR]