Magnetization plateaus in a frustrated spin ½ four-leg nanotube

The magnetic behavior of the spin - ½ Ising system, consisting of a squared four-legs Nanotube connected to each other by different exchange couplings, have been studied by mean of the effective field theory (EFT). The Nano-system can be immersed in an applied homogenous magnetic field. In addition to the transversal J⊥ and longitudinal J//interactions, we attentively examine the influence of the diagonal exchange interaction Jd on the main thermodynamic variables such as internal energy, spontaneous magnetization, isothermal magnetization, and initial susceptibility.The results show that critical temperature is enhanced with increasing the diagonal exchange coupling strength, while the isothermal magnetization curves can display jumps and plateaus at special values of the applied field, especially at lower temperatures. Our study proves also that the sign and the strength of each exchange coupling constant play a key role in the global magnetic behavior of this single-wall squared Nanotube spin. In particular, antiferromagnetic diagonal exchange interaction can lead to strong frustration.