,Magnetic Long-Range Order and Colossal Magnetoresistance Effect in Double Exchange Ladders

• 作 者: 马冬梅 邹良剑
• 机 构: Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031“,”National Laboratory of
• 出 处: 中国物理快报（英文版）
• 发表日期: 2001年9期

By applying Bogoliubovs ineguality to double-exchange(DE) ladders, we show that the ferromagnetic(FM) order is absent in the new DE systems at finite temperatures. The incorporation of Jahn-Teller electron-phonon coupling, orbital degeneracy and on-site Coulomb interaction with the DE interaction do not preserve these orders. The long-wavelength thermal fluctuations of the spins oversome the DEFM correlation and destroy the FM orders. The implication of the absence of FM order on the transport of the DE ladders is discussed.