Magnetic Oscillations in the Nambu - Jona-Lasinio model

Abstract

The phase structure of a simple Nambu-Jona-Lasinio model has been investigated at non-zero values of $\mu$ and H, where H is an external magnetic field and $\mu$ is the chemical potential. On this basis magnetic oscillations effects were considered. It was shown that there are standard (periodic) van Alphen-de Haas magnetic oscillations of some thermodynamical quantities, including magnetization, pressure and particle density in the NJL system. Besides, we have found non-standard, i.e. non-periodic, magnetic oscillations, since the frequency of oscillations is a H-dependent quantity. Finally, there arises an oscillating behaviour not only for thermodynamical quantities, but also for a dynamical quantity like the quark mass. The possibility for magnetic oscillations of some physical quantities inside neutron stars is discussed.