Two-dimensional superfluid Fermi liquid with p-pairing

Alexander I. Akhiezer, Красильников Владимир Владимирович, S.V. Peletminskii +1 more

A. N. Tarasov

General expressions are obtained in explicit form for the anomalous and normal distribution functions of quasiparticles in nonunitary phases of a superfluid paramagnetic Fermi liquid consisting of electrically neutral fermions with triplet pairing (the pairs have spin s=1 and an arbitrary odd value of the orbital angular momentum l) in a uniform static magnetic field. A generalized Fermi-liquid approach is used which takes into account the exchange Fermi-liquid interaction but does not specify the form of the energy functional of the superfluid Fermi liquid. The results are valid at any temperature in the interval 0⩽T⩽Tc, where Tc is the temperature of the phase transition from the normal to the superfluid state. When an explicit form of the energy functional is specified, the general formulas for the distribution function can be used to describe the various nonunitary phases of a superfluid Fermi liquid of the He3 type in a high magnetic field. In particular, for He3-A1, He3-A2, and the nonunitary two-dimensional phase of He3 in a high magnetic field at 0⩽T⩽Tc, an energy functional quadratic in the distribution function is used to find a system of coupled equations for the order parameter and the effective magnetic field and to obtain an expression is obtained for the nonlinear magnetic susceptibility.

Yoshifumi Onishi, Kazumasa Miyake

It is studied which type of superfluidity is induced by the paramagnon-mediated interaction in a two-dimensional isotropic Fermion system. The stability of various types of Cooper pairing is investigated in the framework of strong coupling theory on the basis of the RPA treatment for spin fluctuations. It is shown that the d -wave pairing is the most likely possibility in the two-dimensional isotropic Fermi system with short-range repulsive interaction. This is in marked contrast with the three-dimensional case where the triplet p -wave pairing is stabilized, and gives a prediction for a possible type of superfluidity of 3 He adsorbed on the flat graphite surface.

Lihong Zhou, Wei Yi, Xiaoling Cui

Alexander I. Akhiezer, Красильников Владимир Владимирович, S. V. Peletminskiǐ +1 more

A Fermi-liquid approach to the theory of superfluidity is developed, based on a generalization of the combinatoric expression for the entropy to the case in which the state of the Fermi liquid is described not only by a normal but also by an anomalous distribution function. The energy of the superfluid Fermi liquid is given in the form of a functional of these distribution functions. In the weak-coupling approximation the Fermi-liquid approach is equivalent to the BCS theory. The interaction between the Fermi liquid and an electromagnetic field is gauge invariant. In addition to the singlet-pairing theory the triplet-pairing theory is also developed. A unified variational principle that gives rise to the theory of superfluidity (superconductivity) is used to obtain the London equations and the Ginzburg–Landau equation. Applications of this theory are made to the derivation of an equation for ideal two-component hydrodynamics.