Cyclotron resonance of two-dimensional electron system affected by neighboring quantum dot layer

摘要

We have investigated the cyclotron resonance (CR) in a two-dimensional electron system (2DES) separated by a thin barrier layer from InAs self-assembled quantum dots (QDs). Two absorption peaks of CR of the 2DES were clearly observed, indicating coexistence of free electrons with high mobility and trapped electrons within local potential minima caused by the neighboring QDs. The CR of the trapped electrons changes its intensity, corresponding to the charge state of the QDs. This is the first optical measurements to show that the charge state of the QDs affects on the 2DES in the role as a floating gate.