Advancing DNA quantum computing with electric field gradients and nuclear spins

Sydney, Australia (SPX) Jan 27, 2025
Researchers at Peking University have demonstrated a novel approach to harnessing nuclear electric resonance for manipulating the nuclear spins of nitrogen atoms within DNA molecules. By leveraging electric field gradients, the team achieved artificial control over DNA, showcasing its potential as a medium for quantum computation. The findings, derived from molecular dynamics simulations, quantum chemical computations, and theoretical analyses, reveal how DNA's genetic and structural information can be encoded in the orientations of nitrogen nuclear spins. The study was published on December 12 in the open-access journal Intelligent Computing, under the title "Encoding Genetic and Structural Information in DNA Using Electric Field Gradients and Nuclear Spins."

"Our research has unveiled the patterns of the principal axis directions of the electric field gradient at the nitrogen atom sites in DNA molecules, demonstrating that these directions are closely associated with the types of bases and the 3D structure of DNA," the authors stated. These findings illustrate that nitrogen nuclear spin orientations encapsulate both structural and sequence data of DNA. The study also suggests that by sequencing DNA bases, they could potentially serve as storage mechanisms in DNA-based quantum computing systems, which would require a complementary computational mechanism.

Proton nuclear spins, characterized by their complexity and diverse properties, interact with nitrogen nuclear spins to facilitate computational functionality. This mechanism points to the feasibility of employing DNA molecules as components in quantum computing devices.

Nitrogen atoms within DNA are bonded to either three or two other atoms, leading to distinct electric field gradient orientations. For three bonds, the principal axis is always perpendicular to the DNA base plane. For two bonds, the axis aligns either with the bisector of the bonds or is nearly perpendicular, depending on the nitrogen type and DNA base. These orientations differ across adenine, guanine, cytosine, and thymine. Simulations examining the electric field gradient of adjacent DNA bases revealed consistent alignment between the nuclear spin deflection angles and the structural deflection angles of adenine and guanine. In contrast, cytosine and thymine exhibited greater variability, with no consistent orientation rules.

The researchers conducted molecular dynamics simulations to model the DNA's atomic coordinates over time, ensuring neutrality through a solvated system with added ions. Rigorous equilibration and simulation procedures were applied, followed by quantum chemical analyses of specific nucleotide subsets. By focusing on nitrogen atom positions within DNA bases, the team analyzed electric field gradient components to identify principal axis directions and eigenvalues. Comparing the structural deflection angles of homogeneous DNA bases with the deflection angles of nuclear spins revealed a dependence on DNA structure. Furthermore, the study explored the influence of nitrogen nuclear spins on surrounding proton nuclei under electric field gradients.

This research builds upon the team's prior work, which investigated nuclear electric resonance to control sodium ion nuclear spins on phospholipid membranes. By extending these principles to DNA, the study sheds light on the intricate relationship between electric field gradients, nitrogen atom orientations, and DNA structure. The findings provide a deeper understanding of molecular-level artificial intervention for DNA computation and establish groundwork for innovative quantum computer designs and genetic information processing.

Research Report:Encoding Genetic and Structural Information in DNA Using Electric Field Gradients and Nuclear Spins