Edge-channel interferometer at the graphene quantum Hall pn junction

Authors :: Takashi Taniguchi
Sei Morikawa
Tomoki Machida
Rai Moriya
Satoru Masubuchi
Kenji Watanabe
Publication Year :: 2015
Publisher :: arXiv, 2015.
Abstract: We demonstrate a quantum Hall edge-channel interferometer in a high-quality graphene pn junction under a high magnetic field. The co-propagating p and n quantum Hall edge channels traveling along the pn interface functions as a built-in Aharanov-Bohm-type interferometer, the interferences in which are sensitive to both the external magnetic field and the carrier concentration. The trajectories of peak and dip in the observed resistance oscillation are well reproduced by our numerical calculation that assumes magnetic flux quantization in the area enclosed by the co-propagating edge channels. Coherent nature of the co-propagating edge channels are confirmed by the checkerboard-like pattern in the dc-bias and magnetic-field dependences of the resistance oscillations.<br />Comment: 16 pages, 4 figures, supplementary material: 3 pages, 2 figures