Investigation of on-chip double-shieled QHR device in ac regime

For the investigation of ac performance, two on-chip double-shielded QHR devices and two double-shielded chip carriers were fabricated at National Metrology Institute of Japan and have been studied with ac at Physikalisch-Technische Bundesanstalt. It has been measured that the shape of the i = 2 plateaux at zero shield-potential is not flat and the linear frequency dependence of the quantum Hall resistance amounts to -0.14 (μΩ/Ω) /kHz. Deferent shield designs are proposed to reduce the frequency dependence.