Related papers: Displaced Drude peak from $\pi$-ton vertex correct…
We present a broadband optical-conductivity study of superconducting single-crystalline EuFe2(As1-xPx)2 with three different substitutional levels. We analyze the normal-state electrodynamics by decomposing the conductivity spectra using a…
Artificial tuning of dielectric parameters can result from interface conductivity in polycrystalline materials. In ferroelectric single crystals, it was already shown that ferroelectric domain walls can be the source of such artificial…
Recent experiments find that the pseudogap phase of the high-T$_{c}$ cuprates ends suddenly at an electron doping $x^{*}$ when the Fermi surface change its shape from hole-like to electron-like. In this short note, we argue that the…
We explore multiband effects on d-wave superconducting instabilities driven by electron-electron interactions. Our models on the two-dimensional square lattice consist of a main band with an extended Fermi surface and predominant weight…
We calculate analytically the conductivity of weakly disordered metals close to a "ferromagnetic" quantum critical point in the low temperature regime. Ferromagnetic in the sense that the effective carrier potential $V(q,\omega)$, due to…
The electron-electron interactions affect the low-energy excitations of an electronic system and induce deformations of the Fermi surface. These effects are especially important in anisotropic materials with strong correlations, such as…
The spin-split Fermi level crossings of the conduction band in Ni are mapped out by high-resolution photoemission and compared to the equivalent crossing in Cu. The area of the quasiparticle peak decreases rapidly below Ef in Ni, but not in…
We measured the polarized optical conductivity of URu$_2$Si$_2$ from room temperature down to 5 K, covering the Kondo state, the coherent Kondo liquid regime, and the hidden-order phase. The normal state is characterized by an anisotropic…
Understanding the origin of electron incoherence is the first step toward a theoretical description of the non-Fermi liquid behavior of the high-T$_{c}$ cuprate superconductors. Such electron incoherence manifests itself most evidently in…
Optical reflection measurements within the highly conducting (a,b)-plane of the organic metal (BEDT-TTF)_4[Ni(dto)_2] reveal the gradual development of a sharp feature at around 200 cm as the temperature is reduced below 150 K. Below this…
We present a theoretical description of the differential conductance of point contacts between a normal metal and a multi-band superconductor with extended s\pm pairing symmetry. We demonstrate that the interband impurity scattering…
One of the central tenets of conventional theories of superconductivity, including most models proposed for the recently discovered iron-pnictide superconductors, is the notion that only electronic excitations with energies comparable to…
We compute the spin susceptibility of the two-dimensional Hubbard model away from half-filling, and analyze the impact of frequency dependent vertex corrections as obtained from the dynamical mean field theory (DMFT). We find that the local…
Monolayer transition metal dichalcogenides (TMDs) have the potential to unlock novel photonic and chemical technologies if their optoelectronic properties can be understood and controlled. Yet, recent work has offered contradictory…
Electronic nematicity is often found in unconventional superconductors, suggesting its relevance for electronic pairing. In the strongly hole-doped iron-based superconductors, the symmetry channel and strength of the nematic fluctuations,…
The paraconductivity, originating from critical superconducting order-parameter fluctuations in the vicinity of the critical temperature in a layered superconductor is calculated in the frame of the self-consistent Hartree approximation,…
The interband optical absorption of linearly polarised light by two-dimensional (2D) semimetals hosting tilted and anisotropic Dirac cones in the bandstructure is analysed theoretically. Super-critically tilted (type-II) Dirac cones are…
Superconductivity is a quantum phenomenon caused by bound pairs of electrons. In diverse families of strongly correlated electron systems, the electron pairs are not bound together by phonon exchange but instead by some other kind of…
In one dimension density-density interactions of particles reduce their mobility and hence the Drude weight, which controls the divergence of the optical conductivity at zero frequency, decreases. We study effects of pair hopping events on…
In modern transformation optics, one explores metamaterials with properties that vary from point to point in space and time, suitable for applications in devices such as an "optical invisibility cloak" and an "optical black hole". We…