Magnon side band in Rb2CoF4 under a high magnetic field

Abstract A clear nonlinear Zeeman effect of magnon side band lines in a uniaxial antiferromagnet Rb 2 CoF 4 is observed above 100 kOe by using a pulsed high magnetic field. The nonlinearity is explained by considering the spin-orbit interaction in the excited 2 T 1 ( 2 P) triplet of the Co 2+ ion.