Heat capacity and spin susceptibility of two-dimensional t–J model

• Published in: Физика низких температур
• Date: 2007
• Main Authors: Antsygina, T.N., Poltavskaya, M.I., Poltavsky, I.I., Chishko, K.A.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2007
• Subjects: Related Topics
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/121799
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Heat capacity and spin susceptibility of two-dimensional
 t–J model / T.N. Antsygina, M.I. Poltavskaya, I.I. Poltavsky, K.A. Chishko // Физика низких температур. — 2007. — Т. 33, № 6-7. — С. 814-819. — Бібліогр.: 14 назв. — англ.

Thermodynamic properties of the t–J model on square and triangular lattices near half-filling are investigated
 theoretically within an analytical approach based on the Kondo and Yamaji’s Green function decoupling
 scheme. The temperature dependences of the heat capacity and spin susceptibility are calculated in the wide
 temperature range for the case when the exchange constant J is greater than the hopping amplitude t. It was
 found, that with the increase of doping from the half-filling, the maximum of the spin susceptibility increases
 and its position shifts to lower temperatures for both types of lattices. Such behavior is in agreement with the
 qualitative predictions [E. Dagotto, Rev. Mod. Phys. 66, 763 (1994)]. Heat capacity demonstrates a double
 peak shape. The high temperature peak associated with the «spin wave-like» excitations shifts to lower temperatures
 with doping. The low temperature peak appears due to the holes and its height and position depend
 on both the doping and the ratio t / J .