Peptides as versatile scaffolds for quantum computing

In this work we showcase the potential of peptides as versatile scaffolds for quantum computing and molecular spintronics. In particular, we focus on lanthanide-binding tags, which were originally developed in the field of biotechnology for the study of protein structure and dynamics. Firstly, we demonstrate quantum coherent oscillations in a Neodymium peptidic qubit. Then, employing bacterial biosynthesis, we investigate the possibility of increasing the number of qubits in the same molecular system, with the case studies being a double spin qubit with two distinct coordination environments, and an asymmetric chain of 9 spin qubits with a spin-spin separation of about 2 nm and in an arbitrarily chosen sequence of coordination environments. Finally, we take advantage of biochemical modification for the preparation of paramagnetic, chiral, Self-Assembled Monolayers (SAMs) on Au(111).Our experimental and theoretical characterization shows that this is a promising structure for spintronic applications, and in particular to improve on two state-of-the-art approaches to molecular spin qubits. We conclude with an overview of the challenges and new opportunities opened by this emerging field.