A write time of 6ns for quantum dot–based memory structures

Abstract

The concept of a memory device based on self-organized quantum dots (QDs) is presented, enabling extremely fast write times, limited only by the charge carrier relaxation time being in the picosecond range. For a first device structure with embedded InAs∕GaAs QDs, a write time of 6ns is demonstrated. A similar structure containing GaSb∕GaAs QDs shows a write time of 14ns. These write times are independent of the localization energy (e.g., storage time) of the charge carriers and at the moment are limited only by the experimental setup and the parasitic cutoff frequency of the RC low pass of the device.