An exact fermion model with monopole and quadrupole pairing

Joseph N. Ginocchio

Takaharu Otsuka

Joseph N. Ginocchio

The monopole and quadrupole fermion pairs of a monopole and quadrupole pairing model can be represented by a finite expansion in terms of monopole and quadrupole bosons.

Angel Ricardo Plastino, G.L. Ferri, Angelo Plastino

We employ two different Lipkin-like, exactly solvable models so as to display features of the competition between different fermion–fermion quantum interactions (at finite temperatures). One of our two interactions mimics the pairing interaction responsible for superconductivity. The other interaction is a monopole one that resembles the so-called quadrupole one, much used in nuclear physics as a residual interaction. The pairing versus monopole effects here observed afford for some interesting insights into the intricacies of the quantum many body problem, in particular with regards to so-called quantum phase transitions (strictly, level crossings).

K. A. Penson, M. Kolb

K. A. Penson, M. Kolb