Modulational instability, quantum breathers and two-breathers in a frustrated ferromagneti

Modulational instability, quantum breathers and two-breathers in a frustrated ferromagnetic spin

lattice under an external magnetic field

Wanhan Su;Jiayu Xie;Tianle Wu;Bing Tang

【期刊名称】《中国物理：英文版》 【年(卷),期】2024(027)009

【摘要】The modulational instability,quantum breathers and two-breathers in a frustrated easy-axis ferromagnetic zig-zag chain under an external magnetic field are investigated within the Hartree approximation.By means of a linear stability analysis,we analytically study the discrete modulational instability and analyze the effect of the frustration

strength

on

the

discrete

modulational

instability

region.Using the results from the discrete modulational instability analysis,the presence conditions of those stationary bright type localized solutions are presented.On the other hand,we obtain the analytical expressions for the stationary bright localized solutions and analyze the effect of the frustration on their emergence con-ditions.By taking advantage of these bright type single-magnon bound wave functions obtained,quantum breather states in the present frustrated ferromagnetic zig-zag lattice are constructed.What is more,the analytical forms for quantum two-breather states are also obtained.In particular,the energy level formulas of quantum breathers and two-