Related papers: Nonlocal optical conductivity of Fermi surface nes…
Half-metals have fully spin polarized charge carriers at the Fermi surface. Such polarization usually occurs due to strong electron--electron correlations. Recently [Phys. Rev. Lett. {\bf{119}}, 107601 (2017)], we have demonstrated…
Fermi liquid theory is remarkably successful in describing the transport and optical properties of metals; at frequencies higher than the scattering rate, the optical conductivity adopts the well-known power law behavior $\sigma_1(\omega)…
Half-metallicity (full spin polarization of the Fermi surface) usually occurs in strongly correlated electron systems. We demonstrate that doping a spin-density wave insulator in the weak-coupling regime may also stabilize half-metallic…
We study the scaling behaviour of the optical conductivity $(\sigma)$, free energy density $(F)$, and shear viscosity of the quantum critical point associated with the spin density wave phase transition for a two-dimensional metallic system…
The optical conductivity of quasicrystals is characterized by two features not seen in ordinary metallic systems. There is an absence of the Drude peak and the interband conductivity rises linearly from a very low value up to normal…
Fermi arc surface states, a hallmark of topological Dirac semimetals, can host carriers that exhibit unusual dynamics distinct from that of their parent bulk. Here we find that Fermi arc carriers in intrinsic Dirac semimetals possess a…
Presence of magnetism in potentially altermagnetic RuO$_2$ has been a subject of intense debate. Using broadband infrared spectroscopy combined with density-functional band-structure calculations, we show that optical conductivity of…
Topological nodal-line semimetals are characterized by symmetry-protected one-dimensional band-touching lines or loops, which give rise to their peculiar Fermi surfaces at low energies. Furthermore, if time-reversal or inversion symmetry…
We report the optical conductivity in high-quality crystals of the chiral topological semimetal CoSi, which hosts exotic quasiparticles known as multifold fermions. We find that the optical response is separated into several distinct…
The frequency-dependent conductivity is studied for both the one-dimensional Hubbard model and a model of spinless fermions, using a selection rule, the Bethe ansatz energy eigenstates, and conformal invariance. For densities where the…
We study the frequency dependence of the electron self energy and the optical conductivity in a recently developed field theory of the spin density wave quantum phase transition in two dimensional metals. We focus on the interplay between…
The Fe-based Oxypnicide superconductors have generated a huge amount of interest; they are a high temperature superconductor, with a Tc of 55K, but do not have the two dimensional copper oxygen layer that was thought essential for…
We consider the possibility of formation of an unconventional spin density wave (USDW) in quasi-one dimensional electronic systems. In analogy with unconventional superconductivity, we develop a mean field theory of SDW allowing for the…
We study the frequency-dependent conductivity of nodal line semimetals (NLSMs), focusing on the effects of carrier density and energy dispersion on the nodal line. We find that the low-frequency conductivity has a rich spectral structure…
We performed optical spectroscopy measurement on single crystals of BaFe$_2$As$_2$ and SrFe$_2$As$_2$, the parent compounds of FeAs based superconductors. Both are found to be quite metallic with fairly large plasma frequencies at high…
The recently discovered FeAs-based materials exhibit a $(\pi,0)$ Spin Density Wave (SDW) in the undoped state, which gives way to superconductivity upon doping. Here we show that due to an interesting topological feature of the band…
Magnetic ordering of the first row transition metal intercalates of NbS$_2$ due to coupling between the conduction electrons and the intercalated ions has been explained in terms of Fermi surface nesting. We use angle-resolved photoelectron…
Based on density functional calculations, the relationship between magnetism or superconductivity and electronic states around Fermi level were derived, and the location of the Fermi level in nonmagnetic "form" of Laves-phase compounds is…
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…
The peculiar shape of the Fermi surface of topological nodal line semimetals at low carrier concentrations results in their unusual optical and transport properties. We analytically investigate the linear optical responses of three and…