Deterministic Storage of Quantum Information in the Genetic Code

Abstract: DNA has been proposed as a chemical platform for computing and data storage, paving the way for building DNA-based computers. Recently, DNA has been hypothesized as an ideal quantum computer with the base pairs working as Josephson junctions. There are still major challenges to be overcome in these directions, but they do not prevent deviceful perspectives of the main problem. The present paper explores DNA base pairs as elementary units for a scalable nuclear magnetic resonance quantum computer (NMRQC). First, it presents an overview of the proton transfer (PT) mechanism during the prototropic tautomerism in the base pairs, scoring the current stage. Second, as a proof-of-principle, the paper examines these molecular structures as quantum processing units (QPUs) of a biochemical quantum device. For the model proposed here, it is theoretically demonstrated that the nuclear spins involved in the PT of base pairs can be deterministically prepared in a superposition of triplet states. Under appropriate conditions, the proton dynamics provides the minimal two-qubit entanglement required for quantum computing. The dynamics between the canonical and tautomeric quantum states (CQS and TQS, respectively) is determined from a thermally dependent Watson-Crick quantum superposition (WCQS); i.e., |WCQS> = a(T)|CQS> + b(T)|TQS> with |a(T)|^2 + |b(T)|^2 = 1. If the DNA structure is sufficiently protected to avoid environment-induced decoherence of the confined-proton quantum states, quantum information can be successfully encoded in several base pairs along the coiled double strand. As a potential applicability, a crystalline DNA device could be employed for quantum computing and cryptography controlled by a sequence of Ramsey pulses. Finally, this study critically evaluates these possibilities toward a proof-of-concept of a DNA-based quantum computer.