Electrical manipulation of dynamic magnetic impurity and spin texture of helical Dirac fermions Rui-Qiang Wang, Min Zhong, Shi-Han Zheng, Mou Yang and Guang-Hui Wang EPL, 114 3 (2016) 37007 Published online: 31 May 2016 DOI: 10.1209/0295-5075/114/37007