Entanglement generation in few-nucleon scattering

TL;DR

This paper investigates how quantum entanglement is generated during elastic scattering of few-nucleon systems, revealing that entanglement is generally weaker in these systems compared to simpler nucleon-nucleon interactions, especially considering Coulomb effects.

Contribution

It introduces a method to calculate entanglement power for charged nucleon systems using screening, and compares entanglement generation in different few-nucleon scatterings, highlighting symmetry effects.

Findings

Entanglement power is smaller in proton-Helium-3 and neutron-Tritium scattering than in neutron-proton scattering.

Coulomb interactions suppress entanglement generation in charged nucleon scatterings.

Effective field theories with enhanced symmetry show reduced entanglement capacities.

Abstract

Inspired by a recent Letter [S. R. Beane et al., Phys. Rev. Lett. 122, 102001(2019)], the entanglement generated in the elastic $S$-wave scattering of $p+{}^{3}\text{He}$ and $n+{}^3\text{H}$ is studied, where the proton, neutron, ${}^{3}$He, and ${}^3$H are all regarded as qubits. To deal with the Coulomb interaction between the proton and ${}^{3}$He, we derive the entanglement power, a physical quantity that measures the average entanglement generated by a scattering process, for charged qubits within the screening method. The entanglement power in the aforementioned two few-nucleon scatterings is found to be generally much smaller than that in the $S$-wave $n+p$ scattering at low energies, with the corresponding cluster effective field theories possessing an enhanced approximate $\text{SU}(2)_1\otimes\text{SU}(2)_{2}$ symmetry at leading order. Our study suggests that the entanglement generation capacities of effective interactions between nucleons and light nuclei could be more suppressed than realistic nucleon-nucleon interactions at low energies.