Ferrimagnetism induced by asymmetrical ferromagnetic next-nearest-neighbour exchange interactions in an antiferromagnetic spin-1/2 zigzag chain

【摘要】 The magnetic properties of an antiferromagnetic bond alternating spin-1/2 zigzag chain with asymmetrical ferromagnetic next-nearest-neighbour exchange interactions at finite temperature are investigated by using the many-body Green’s function theory.It is found that the ferrimagnetic ordering does not appear in the symmetrical next-nearestneighbour coupling case,and takes place only for the asymmetrical next-nearest-neighbour case at finite temperature rather than the ground state.Furthermore,as the asymmetry degree of the next-nearest-neighbour exchange interactions increases,the ferrimagnetism becomes more and more dominant.It is shown that the elementary excitation spectra are responsible for the observed magnetic behaviour.更多还原

【Abstract】 The magnetic properties of an antiferromagnetic bond alternating spin-1/2 zigzag chain with asymmetrical ferromagnetic next-nearest-neighbour exchange interactions at finite temperature are investigated by using the many-body Green’s function theory.It is found that the ferrimagnetic ordering does not appear in the symmetrical next-nearestneighbour coupling case,and takes place only for the asymmetrical next-nearest-neighbour case at finite temperature rather than the ground state.Furthermore,as the asymmetry degree of the next-nearest-neighbour exchange interactions increases,the ferrimagnetism becomes more and more dominant.It is shown that the elementary excitation spectra are responsible for the observed magnetic behaviour.更多还原