Towards the quantum noise limit in semiconductor microwave amplifiers: a study of hot electron noise

California Institute Of Technology, Pasadena CA

Investigators

Abstract

Nontechnical: Semiconductor microwave amplifiers are widely used in science and technology. They are widely used, ranging from fundamental science such as the detection of dark matter to applications such as the identification of hazardous chemicals. As they operate at the beginning of the detection circuit, amplifiers are often the main factor limiting the sensitivity of these technologies. The PI will investigate the sources of quantum noise in microwave amplifiers by experiment and theory. Predictions of how noise can be decreased will be experimentally tested through design and characterization of custom devices. The aim of this work is a transformative advance towards reducing noise in microwave amplifiers to the ultimate limit. Technical: This project will investigate the precise microscopic origins of electronic noise in high electron mobility transistors using advances in numerical tools and characterization of custom devices. Electron noise in semiconductor devices, arising from fluctuations due to scattering and other mechanisms, must be mitigated for semiconductor amplifiers to approach the quantum noise limit but the microscopic details at the level of individual electronic and vibrational states have been inaccessible. Investigators will employ theoretical and numerical descriptions of carrier transport at such scales to quantitatively identify the contributions of diverse transport processes to noise and how they may be mitigated. Predictions of how noise can be decreased by modifications of device architecture obtained from such studies will be directly experimentally tested using characterization of custom devices. This project will also train students in the microwave electronic technology that is presently in high demand for engineering of quantum hardware such as quantum computers. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.