“Engineering Molecular Spins for Telecom Band Emission”

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 over long distances. To achieve this, prospective materials for quantum networking must emit in fiber optics’ low-loss optical transmission window centered at 1550 nm, known as the “telecom band.” Vanadium dopants in silicon carbide have demonstrated near-infrared emission around 1850 nm within a spin-photon interface, but these dopants lack tunability over their optical properties. Our work combines the promising electronic structure of these dopants and the inherent tunability of molecules to design and synthesize luminescent paramagnetic vanadium complexes that can achieve telecom band emission and finetuned control over optical properties. In the first part of my talk, I will outline our two- pronged approach to target telecom band emission in a series of vanadium(III)-based complexes: stabilization of the emissive excited state and destabilization of the ground state relative to the emissive excited state. These two strategies culminate in a series of vanadium(III) complexes which tune emission wavelength from 1220 nm to the desired value of 1550 nm, achieving telecom band emission. In the second part of my talk, I will discuss the impact of these strategies on the magnetic properties and spin dynamics of these molecules 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 for quantum networking applications.