ISSN:
1434-6036
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract. With the aid of the Schwinger-boson mean-field method, we study the low-lying excitations and thermodynamic properties of a ferrimagnetic Heisenberg two-leg ladder (i.e., a ferrimagnetic double-chain with an antiferromagnetic interaction). The interaction between the two chains plays an important role in producing a low-lying excitation energy gap, affecting the low-lying excited spectrum, and increasing the disorder of the ferrimagnetic double-chain. The excitation spectrum, energy gap, and spin reduction in the ground state are calculated. Thermodynamic quantities such as the short-range spin correlation and short-range order are also obtained at low temperatures. In this gapful system, we observed the exponential behaviors in both the specific heat (C V ) and the product of magnetic susceptibility and temperature ( $\chi T$ ) at low temperatures. The exponential behavior of the $\chi T$ versus temperature agrees qualitatively with the experimental results in $\rm NiCu(pba)(D_2O)_3\cdot D_2O$ at low temperatures.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1140/epjb/e2004-00043-y
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