Quantum information informing nuclear structure calculations*

Quantum information is a hot topic, but aside from quantum computing and quantum cryptography, does it have any practical uses? In fact, it can be used to design useful approximations to difficult calculations. First we show that, in nuclear shell-model calculations, the proton and neutron partitions of the wave functions are weakly entangled, even more so for nuclear away from N = Z. Other numerical work has shown that among different partition schemes the proton-neutron entanglement is the lowest. Building upon this, we have developed a 'weak entanglement approximation' which efficiently builds a basis for large-scale shell model calculations, including in model spaces far beyond what current codes can reach. We plan to use this approach to push the configuration-interaction shell model further than even before applied.