Quantum phase transition in even–even molybdenum isotopes using von Neumann entropy

In this study, the von Neumann entropy (entanglement entropy) of s– d bosons and proton (π)–neutron (ν) bosons in the even–even molybdenum ( 94–102 Mo) isotopes, within the framework of the Interacting Boson Model-2, has been calculated and analyzed. In order to compare the results, the energy spectra, quadrupole moment, and the expectation value of the s-boson number operator of Mo isotopes have been obtained. The results showed that 94 Mo has the minimum entanglement of s and d bosons and 102 Mo nucleus has the maximum entanglement of s and d bosons. Therefore, these nuclei are spherical (U(5)) and γ-unstable (SO(6)) nuclei, respectively, and other observables confirm this result. Also, the value of the entanglement entropy of the π and ν bosons is constant by changing the control parameter. So, it does not show any transition.