Miniaturized Chip-Scale Quantum and Terahertz Systems Through Tight Integration of Electronics, Electromagnetics, and Qubits

Abstract

The utilization of electromagnetic waves in quantum information science and the least-explored terahertz (THz) regime are posed to revolutionize sensing, computing, and communication. The key to the prosperity of such a frontier is the development of integrated circuits that enable high-precision and high-flexibility manipulation of the RF-to-optical spectrum. This thesis presents innovations of chip-scale quantum and THz systems, which allow for significant miniaturization, practical solutions, and exciting research opportunities across the device, circuit, and system levels. To illustrate such opportunities, we propose two chip-scale systems realized through tight integration of electronics, electromagnetics, and qubits on CMOS technology. The first one is a hybrid CMOS magnetometer that integrates the essential microwave and optical components to control and measure the field-sensitive quantum states of the solid-state nitrogen-vacancy (NV) centers in diamond. This hybrid architecture is a step to achieve compact and scalable integrated platforms towards quantum-enhanced sensing and information processing. The second system is a package-less THz identification tag (THzID) in CMOS, the smallest monolithic ID chip with far-field communication capability, beam steering, and asymmetric cryptography. This ID opens the door to aggressively utilize the overlooked size shrinkage aspect of THz technology while sustaining broad-bandwidth and low-power operation. The thesis is concluded with potential improvements and perspectives for future work, in addition to several research directions that utilize the advantages of wireless communication and quantum systems, enabling new paradigms in sensing, computing, and communication infrastructures.