Negative differential resistance in parallel single-walled carbon nanotube contacts - Qihang Liu; Guangfu Luo; Rui Qin; Hong Li; Xin Yan; Chengyong Xu; Lin Lai; Jing Zhou; Shimin Hou; Enge Wang; Zhengxiang Gao; Jing Lu (Physical Review B - Condensed Matter and Materials Physics, 2011)