相关论文: Orbital order from the on-site orbital attraction
The FeSe nematic phase has been the focus of recent research on iron based superconductors (IBSs) due to its unique properties. A number of electronic structure studies were performed to find the origin of the phase. However, such attempts…
The rich variety of iron-based superconductors and their complex electronic structure lead to a wide range of possibilities for gap symmetry and pairing components. Here we solve in the 2-Fe Brillouin zone the full frequency-dependent…
We propose that cuprate superconductors are in the vicinity of a spontaneous d-wave type Fermi surface symmetry breaking, often called a d-wave Pomeranchuk instability. This idea is explored by means of a comprehensive study of magnetic…
Recent angle-resolved photoemission measurements on La$_3$Ni$_2$O$_7$ have challenged the density-functional-theory-based picture of three Fermi surfaces by revealing that the $d_{z^2}$-derived $\gamma$ band can reside below the Fermi…
We present the theory of orbital ordering in orbital-degenerate itinerant electron systems. After proposing the criterion of instability for orbital ordering or orbital density wave ordering, we find that the orbital and the spin-orbital…
We report extensive measurements of quantum oscillations in the normal state of the Fe-based superconductor LaFePO, (Tc ~ 6 K) using low temperature torque magnetometry and transport in high static magnetic fields (45 T). We find that the…
We analyze the leading vestigial instability due to the melting of a bidirectional pair-density-wave state in two dimensions. In a previous work by one of the authors, it was found that the interplay between pair-density-wave fluctuations…
Motivated by the unexplored complexity of phases present in the multiorbital Hubbard model, we analyze in this work the behavior of a degenerate two-orbital anisotropic Hubbard model at half filling where both orbitals have equal bandwidths…
The structurally simplest Fe-based superconductor FeSe with a critical temperature $T_{c}\approx$ 8.5 K displays a breaking of the four-fold rotational symmetry at a temperature $T_{s}\approx 87$ K. We investigated the electronic properties…
The primordial ingredient of cuprate superconductivity is the CuO2 unit cell. Here, theoretical attention usually concentrates on the intra-atom Coulombic interactions dominating the 3d^9 and 3d^10 configurations of each copper ion.…
One of the central issues in the recent study of cuprate superconductors is the interplay of charge order with superconductivity. Here the interplay of charge order with superconductivity in cuprate superconductors is studied based on the…
Loop current order has been reported in the pseudogap regime of a few cuprate systems in polarized neutron scattering experiments. Here we study several observable consequences of such order in the d-wave superconducting state at low T. The…
We present evidence for the existence of a spontaneous instability towards an orbital loop-current phase in a multiorbital Hubbard model for the CuO$_2$ planes in cuprates. Contrary to the previously proposed $\theta_{II}$ phase with…
Orbital differentiation is a common theme in multiorbital systems, yet a complete understanding of it is still missing. Here, we consider a minimal model for orbital differentiation in Hund metals with a highly accurate method: We use the…
Phase diagram of half-doped perovskite manganites is studied within the extended double-exchange model. To demonstrate the role of orbital degrees of freedom both one- and two-orbital models are examined. A rich phase diagram is obtained in…
We explore superconducting instability for a clean two-band layered superconductor with deep and shallow bands in the magnetic field applied perpendicular to the layers. In the shallow band, the quasiclassical approximation is not…
We study the superconducting state of Sr$_2$RuO$_4$ on the bases of a phenomenological but orbital specific description of the electron-electron attraction and a realistic quantitative account of the electronic structure in the normal…
Conduction electrons interacting with a dynamic impurity can give rise to a local Fermi liquid. The latter has the same low energy spectrum as an ideal Fermi gas containing a static impurity. The Fermi liquids's elementary excitations are…
Using angle-resolved photoemission spectroscopy we have studied the low-energy electronic structure and the Fermi surface topology of Fe$_{1+y}$Te$_{1-x}$Se$_x$ superconductors. Similar to the known iron pnictides we observe hole pockets at…
Nonuniform superconducting state due to strong spin magnetism is studied in two-dimensional type-II superconductors near the second order phase transition line between the normal and the superconducting states. The optimum spatial structure…