Semi-classical theory of nuclear reactions

G.M. Vagradov

Stanislav G. Kadmensky

Wolfgang Weidlich

J. J. M. Verbaarschot, Shirô Yoshida

Alessandro Roggero, Chenyi Gu, Alessandro Baroni +1 more

The authors explore methods for developing excited states for a nuclear system in a quantum computer and apply them to the thermal neutron-proton capture reaction, $n+p\ensuremath{\rightarrow}d+\ensuremath{\gamma}$. The applications of this work are a step toward computing nuclear reactions on quantum devices and hold promise for low-energy nuclear theory problems that are hard to solve on classical computers.

Christophe Narth, Natacha Gillet, Bernard C. Levy +2 more

The notion of decoherence is particularly adapted to discuss the quantum-to-classical transition in the context of chemical reactions. Decoherence can be modeled by computing the time evolution of nuclear wave packets evolving on distinct potential energy surfaces, here using density functional theory (DFT) and Born–Oppenheimer molecular dynamics simulations. We investigate a redox cofactor of biological interest (tryptophan tryptophylquinone, TTQ) found in the enzyme methylamine dehydrogenase. We also report the first systematic comparison of semi-empirical DFT (tight-binding DFT) and classical force field approaches for estimating decoherence in molecular systems. In the TTQ cofactor, we find that decoherence combines structural and dynamical aspects: it is initiated by the divergent motions of few atoms and then propagates dynamically to the remaining atoms. It is the mass effect of all the atoms that leads to decoherence within a few femtosecond.