Strong terahertz emission from superlattices via Zener tunneling

¹  Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences Beijing 100080, China
²  Institute for Quantum Information Science, University of Calgary - Calgary, Alberta T2N 1N4, Canada
³  Centre for Quantum Computer Technology, Macquarie University - Sydney, New South Wales 2109, Australia

Corresponding author: kjjin@aphy.iphy.ac.cn

Received: 5 February 2007
Accepted: 4 June 2007

Abstract

We develop a comprehensive, elegant theory to explain terahertz (THz) emission from a superlattice over a wide range of applied electric fields, which shows excellent agreement between theory and experiment for a GaAs/Al_0.3Ga_0.7As superlattice. Specifically we show that increasing the electric field increases THz emission for low fields, then reduces emission for medium fields due to field-induced wave function localization, and then increases emission in the high field due to delocalization and Zener tunneling between minibands. Our theory shows that Zener tunneling resonances yield high THz emission intensities and points to superlattice design improvements.