The electronic structure of Sr2RuO4 is investigated by high angular resolution ARPES at several incident photon energies. We address the controversial issues of the Fermi surface (FS) topology and the van Hove singularity at the M point, showing that a surface state and the replica of the primary FS due to sqrt[2]xsqrt[2] surface reconstruction are responsible for previous conflicting interpret...

The QCD phase diagram as function of the temperature and the baryon chemical potential is the object of many theoretical and experimental investigations. At a high chemical potential, QCD is in the deconfined phase with quarks forming a Fermi surface. It turns out that the gluon induced quark interaction is attractive in the diquark channel [1] generating a Cooper instability of the Fermi surfa...

Combining old and new de Haas-van Alphen (dHvA) and magnetoresistance data, we arrive at a detailed picture of the Fermi surface of the heavy fermion superconductor UPt3. Our work was partially motivated by a new proposal that two 5f valence electrons per formula unit in UPt3 are localized by correlation effects agreement with previous dHvA measurements of the Fermi surface was invoked in its s...

Synchrotron radiation-based x-ray photoemission spectroscopy was used to study the surface Fermi level position within the band gap for thin metal overlayers of Au, Al, Ni, Ti, Pt, and Pd on n–GaN and p–GaN. Nonequilibrium effects were taken into account by measuring the Fermi edge of the metal overlayer. There are two different behaviors observed for the six metals studied. For Au, Ti, and Pt,...

In conventional BCS superconductors, the quantum condensation of superconducting electron pairs is understood as a Fermi surface instability, in which the low-energy electrons are paired by attractive interactions. Whether this explanation is still valid in high-Tc superconductors such as cuprates and iron-based superconductors remains an open question. In particular, a fundamentally different ...

We propose a new type of Hopf semimetals indexed by a pair of numbers (p, q), where the Hopf number is given by pq. The Fermi surface is given by the preimage of the Hopf map, which consists of loops nontrivially linked for a nonzero Hopf number. The Fermi surface forms a torus link, whose examples are the Hopf link indexed by (1, 1), the Solomon’s knot (2, 1), the double Hopf-link (2, 2) and t...

We examine a two-dimensional Fermi liquid with a Fermi surface which touches the Umklapp surface first at the 4 points (±π/2, ±π/2) as the electron density is increased. Umklapp processes at the 4 patches near (±π/2, ±π/2) lead the renor-malization group equations to scale to strong coupling resembling the behavior of a 2-leg ladder at half-filling. The incompressible character of the fixed poi...

We examine a two-dimensional Fermi liquid with a Fermi surface which touches the Umklapp surface first at the 4 points (±π/2, ±π/2) as the electron density is increased. Umklapp processes at the 4 patches near (±π/2, ±π/2) lead the renor-malization group equations to scale to strong coupling resembling the behavior of a 2-leg ladder at half-filling. The incompressible character of the fixed poi...

We review the non-Fermi or marginal liquid behavior of a relativistic QED plasma. In this medium a quasiparticle has a damping rate that depends linearly on the distance between its energy and the Fermi surface. We stress that this dependence is due to the long-range character of the magnetic interactions in the medium. Finally, we study how the quark damping rate modifies the gap equation of c...