Developing Telecom Band-Compatible Molecular Color Centers for Quantum Networking

Abstract

Quantum networking is a new modality of information transmission that will revolutionize the future of telecommunications. However, the realization and widespread use of quantum networking demands low signal loss and distortion over long distances. To achieve this, prospective materials for quantum networking must emit in fiber optics’ optical communications band defined as 1260 to 1625 nm, commonly known as the “telecom band.” Vanadium dopants in silicon carbide have demonstrated near-infrared emission combined with a spin-photon interface, but these systems lack tunability over emission wavelength, preventing emission in the telecom band. This thesis combines the promising electronic structure of these dopants and the inherent tunability of molecular systems to create a family of luminescent paramagnetic vanadium complexes that can achieve both telecom band emission and generalized finetuned control over emission wavelength. Chapters 2 and 3 will outline approaches to target telecom band emission in a series of V_III complexes through a gradual and controlled increase of metal-ligand bonding covalency. This strategy culminates in a series of V_III complexes which tune emission wavelength from 1237 nm to 1424 nm, achieving emission into the telecom band. Chapter 4 will discuss the impact of these strategies on the magnetic properties and spin dynamics of these systems through an analysis of their behavior under high-frequency high-field EPR spectroscopy. This work provides a blueprint for the next generation of molecular spins with optical addressability in the near-infrared regime for applications in quantum networking.