Abstract
Properties of a fermion system at zero temperature are investigated. The physical system is described by a Hamiltonian containing the BCS interaction and an attractive four-fermion interaction. The four-fermion potential is caused by attractions between Cooper pairs mediated by the phonon field. In this paper, the BCS interaction is assumed to be negligible and the four-fermion potential is the only one that acts in the system. The effect of the pairing symmetry used in the four-fermion potential on some zero-temperature properties is studied. This especially concerns the electromagnetic response of the system to an external magnetic field. It turns out that, in this instance, there are serious differences between the conventional BCS system and the one investigated in this paper.
Highlights
Recent decades have been witnessing many new phenomena discovered in solid-state physics
Our objective is to demonstrate the existence of the Meissner–Ochsenfeld effect in the system described by the Hamiltonian H f = Hg + H 0, where H 0 represents the perturbation due to a weak static external electromagnetic field described by the vector potential A(r)
The system with the four-fermion attraction has been investigated in this paper
Summary
Recent decades have been witnessing many new phenomena discovered in solid-state physics (e.g., high temperature superconductivity, heavy fermion superconductors and unusual properties of 3 He) These discoveries are intriguing and lead to many new questions on the nature of superconductivity and superfluidity. We still do not know how many particles are engaged in constituting the fundamental clusters responsible for the occurrence of new phases Is it possible that only two-particle entities are relevant to these systems (e.g., Cooper pairs) or may three or four-particle structures be taken into account? Let us start with a work by Schneider and Keller [2] who measured the relationship between the critical temperature and zero temperature condensate density for some cuprates and Chevrel-phases superconductors They noticed that the experimental data for YBa2 Cu3 O6.602 , for example, ca be associated with the behavior of a dilute Bose gas. Two papers [5,6] reported on a discovery of the half-h/2e magnetic flux quanta coexisting together with the usual ones in SQUIDs fabricated
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
