Novel Transport Properties in Monolayer Graphene with Velocity Modulation
SUN Li-Feng1, FANG Chao1**, LIANG Tong-Xiang2
1Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 2Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084
Abstract：We investigate the transport properties of Dirac fermions through velocity-modulation structures, with the Fermi velocity inside the barriers larger than the one outside. It is shown that the transmission exhibits pseudo-periodicity with the incident angle below the critical transmission angle, but attenuates exponentially in the opposite situation. It is found that in the transmission, (1) the pseudo-periodicity turns to periodicity with suitable modulation; (2) line-type peaks appear in the exponential attenuation region for multiple velocity barriers; (3) peak splitting occurs with the number of the velocity barriers increasing. Some sharp oscillations with the falling-edge slopes close to infinity exist in the conductance profile. These novel transport properties suggest significant potential applications in graphene-based devices.
2013, Vol. 30 
