The left-handed wave inside natural materials

In terms of genetic algorithm (GA) and a parameter tracking scheme (PTS), the propagating constants of a waveguide filled with dissipative magnetic substances are accurately calculated and thoroughly analyzed. The practical results show the method is efficient and accurate. Moreover, it is found during the calculating that under certain conditions, the phase constant may be negative, which revealed that the wave propagating inside this waveguide possess the characteristic of that of the left-handed wave (LHW). It is of significance that the LHW may present in nature materials.