Abstract To understand the mechanism of the fermion pair and fermion-antifermion pair condensation,the solutions of Bethe-Salpeter equation in QED3 is examined.In the ladder appoximation our solution for the axial-scalar is consistent with Ward-Takahashi-identity for the axial vector currents.Since the massless scalar-vector sector is described by a coupled integral equation,it is difficult to ...

Abstract To understand the mechanism of the fermion pair and fermion-antifermion pair condensation,the solutions of Bethe-Salpeter equation in QED3 is examined.In the ladder appoximation our solution for the axial-scalar is consistent with Ward-Takahashi-identity for the axial vector currents.Since the massless scalar-vector sector is described by a coupled integral equation,it is difficult to ...

Exploiting the peculiar properties of proximity-induced superconductivity on the surface of a topological insulator, we propose a device, which allows the creation of a Majorana fermion inside the core of a pinned Abrikosov vortex. The relevant Bogolyubov-de Gennes equations are studied analytically. We demonstrate that in this system the zero-energy Majorana-fermion state is separated by a lar...

We show that one-dimensional binary mixtures of bosons or of a boson and a spin-polarized fermion are Luttinger liquids with the following instabilities: (i) For different particle densities, strong attraction between the mixture components leads to collapse, while strong repulsion leads to demixing, and (ii) For a low-density mixture of two gases of impenetrable bosons (or a spin-polarized fer...

The behavior of the electronic system of heavy fermion metals is considered. We show that there exist at least two main types of the behavior when the system is nearby a quantum critical point which can be identified as the fermion condensation quantum phase transition (FCQPT). We show that the first type is represented by the behavior of a highly correlated Fermi-liquid, while the second type ...

We show that composite fermi/bose superfluids can be created in coldatom traps by employing a Feshbach resonance or coherent photoassociation. The bosonic molecular condensate created in this way implies a new fermion pairing mechanism associated with the exchange of fermion pairs between the molecular condensate and an atomic fermion superfluid. We predict macroscopically coherent, Josephson-l...

We study a resonant Bose-Fermi mixture at zero temperature by using the fixed-node diffusion Monte Carlo method. We explore the system from weak to strong boson-fermion interaction, for different concentrations of the bosons relative to the fermion component. We focus on the case where the boson density n(B) is smaller than the fermion density n(F), for which a first-order quantum phase transit...

We study a lattice model comprising four massless reduced staggered fermions in four dimensions coupled through an SU(4) invariant four-fermion interaction. We present both theoretical arguments and numerical evidence that support the idea that the system develops a mass gap for sufficiently strong four-fermi coupling via the formation of a symmetric four-fermion condensate. In contrast to othe...

We study 2-->n inelastic fermion-(anti)fermion scattering into multiple longitudinal weak gauge bosons and derive universal upper bounds on the scales of fermion mass generation by imposing unitarity of the S matrix. We place new upper limits on the scales of fermion mass generation, independent of the electroweak symmetry breaking scale. Strikingly, we find that the strongest 2-->n limits fall...

Condensed-matter systems that are both low-dimensional and strongly interacting often exhibit unusual electronic properties. Strongly correlated electrons with greatly enhanced effective mass are present in heavy fermion compounds, whose electronic structure is essentially three-dimensional. We realized experimentally a two-dimensional heavy fermion system, adjusting the dimensionality in a con...