Semiconductor Photodetectors, Bio‐Material Sensors and Quantum Computers using High Frequency Sound Waves Available to Purchase

We describe a method by which single photons may be detected at frequencies in excess of 1GHz. This is accomplished with the use of surface acoustic waves (SAWs) in undoped gate‐patterned heterostructures which drag excitons into a quantum‐dot detector. The structure could consist of an undoped InGaAs quantum well embedded close to the surface of a GaAs bulk. We will also discuss the plasma excitations in a double quantum well structure whose electron density is modulated by the periodic potential of the SAW. These plasmon resonances may be employed in a detector when a bio‐molecule is on the surface of the heterostructure. This is especially so for two coupled parallel layers. These plasmon resonances may be employed in a detector when the plasma resonances become unstable and radiate energy. The feasibility of a quantum computer using the electron spin driven by these high‐frequency sound waves is currently under investigation. One of the aspects to be considered using SAWs is its application to sensors, detectors and other devices. These devices have the potential of making significant technological advancement in material science. There have been alternative schemes for photodetectors and sensors for detecting bio‐molecules. Alternative architectures for quantum computers exploiting the electron charge and spin have also been suggested. This project is providing students an opportunity to look at these devices critically.