enhancement compared with a photomixer with conventional interdigitated electrodes, which we used as a reference device. We estimated the powers of the devices based on the blackbody power of a Hg lamp, as described in the Methods section and shown in Fig. 3b of this Article. After receiving a communication from J. Mangeney, R. Colombelli, E. Peytavit, J. F. Lampin, M. Jarrahi, S. Barbieri, M. Wanke and M. A. Belkin, we measured the absolute output of our device using a loaned pyrodetector (Gentec-EO, THZ1.5B-BL-USB). We measured the absolute output power to be about 1 mW, instead of 100 mW as initially estimated and shown in Fig. 3b. Due to this error, we wish to retract the Article, even though the reported relative enhancement and the idea of using nanogap electrodes are still valid. We apologize to the readers for any adverse consequences that may have resulted from the paper’s publication. Retraction: Greatly enhanced continuous-wave terahertz emission by nano-electrodes in a photoconductive photomixer