Strong terahertz emission from superlattices via Zener tunneling Peng Han, Kui-juan Jin, B. C. Sanders, Yueliang Zhou, Hui-bin Lu and Guo-zhen Yang EPL, 79 2 (2007) 27001 Published online: 28 June 2007 DOI: 10.1209/0295-5075/79/27001