Relativistic Fermion on a Ring: Energy Spectrum and Persistent Current
Figure 6
Total current (measured in units of (Figure 3)) for 100 (Blue) and 101 (red dashed) particles in a ring with (). Masses and corresponding values are written on the top of each plot. For large mass, (a) total current depends linearly on flux. As we decrease the mass (b) the dependence becomes nonlinear. For critical mass (12), total current is a step function of flux (c), the step heights being multiple of (13). For lower mass (d), total current tends to diverge at values given by (14), the mean position of the plateaus being multiple of . On further decrease of mass (e), the spectrum becomes narrower and the divergences come closer to the integral flux values. As we go to the zero mass limit (f), total current appears as sharp pulses at integral values of flux.
