Fig. 1From: Fabrication of ion-trap electrodes by self-terminated electrochemical etchingNeedle electrodes are used in different types of the Paul traps for trapped ion quantum information. a The 3-fork needle trap used by our IUPUI-USTC group. b A single 171 Yb + trapped in a). c The “tack” trap [5]. d The four-rod linear traps [11]Back to article page