We report the detection of novel zero-resistance states induced by electromagnetic wave excitation in ultra high mobility GaAs/AlGaAs heterostructure devices, at low magnetic fields, $B$, in the large filling factor limit. Vanishing resistance is observed in the vicinity of $B = [4/(4j+1)] B_{ f}$, where $B_{ f} = 2\pi\textit{ f}m^{ *}/e$, where m$^{ *}$ is the effective mass, e is the charge, and \textit{ f} is the microwave frequency. The dependence of the effect is reported as a function of \textit{ f}, the temperature, and the power.
Categories: cond-mat.mes-hall