Giant Terahertz Photoconductance of Quantum Point Contacts in the Tunneling Regime

Abstract

Filling the ``terahertz gap'' is a prime technological goal. In this study, a quantum point contact (QPC) operating in the tunneling regime changes its conductivity by more than two orders of magnitude in response to rather weak THz light. This change, caused by photon-assisted tunneling, shows that QPCs under these conditions are good candidates for detectors of THz and microwave radiation. Such detector elements do not require antennas, are small, and are easily fabricated by planar technology, and thus can be handily integrated into optoelectronic circuitry.