Related papers: Distinct electronic nematicities between electron …
We performed high-field magnetotransport and magnetization measurements on a single crystal of the 122-phase iron pnictide Ba(Fe1-xCox)2As2. Unlike the HTS cuprates and 1111-phase oxypnictides, Ba(Fe1-xCox)2As2 showed practically no…
Anisotropic charge transport is observed in a two-dimensional (2D) hole system in a perpendicular magnetic field at filling factors nu=7/2 and nu=11/2 for temperatures below 150mK. In stark contrast, the transport at nu=9/2 is isotropic for…
75As NMR and susceptiblity were measured in a Ba(Fe1-xCox)2As2 single crystal for x=6% for various field H values and orientations. The sharpness of the superconducting and magnetic transitions demonstrates a homogeneity of the Co doping x…
We report optical spectroscopic measurements on electron- and hole-doped BaFe2As2. We show that the compounds in the normal state are not simple metals. The optical conductivity spectra contain, in addition to the free carrier response at…
We present an Angle-Resolved PhotoElectron Spectroscopy study of the changes in the electronic structure of electron doped Ba(Fe(1-x)Co(x))2As2 across the superconducting phase transition. By changing the polarization of the incoming light,…
Electronic nematic behavior has been identified and studied in iron-based superconductors for some time, particularly in the well-known BaFe$_2$As$_2$ system, where it is well-known to compete with superconductivity. On the other hand, it…
We review our recent experimental results on the electronic nematic phase in electron- and hole-doped BaFe$_2$As$_2$ and FeSe. The nematic susceptibility is extracted from shear-modulus data (obtained using a three-point-bending method in a…
We use polarization-resolved Raman spectroscopy to study the anisotropy of the electronic characteristics of the iron-pnictide parent compounds $A$Fe$_{2}$As$_{2}$ ($A$~=~Eu, Sr). We demonstrate that above the structural phase transition at…
We report a systematic investigation, together with a theoretical analysis, of the resistivity and Hall effect in single crystals of Ba(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$, over a wide doping range. We find a surprisingly great disparity…
The origin of the electronic nematicity in FeSe is one of the most important unresolved puzzles in the study of iron-based superconductors. In both spin- and orbital-nematic models, the intrinsic magnetic excitations at $\mathbf{Q}_1=(1,…
The two-dimensional electron system in (110)Al$_2$O$_{3-\delta}$/SrTiO$_3$ heterostructures displays anisotropic electronic transport. Largest and lowest conductivity and electron mobility $\mu$ are observed along the $[001]$ and…
The intriguing role of nematicity in iron-based superconductors, defined as broken rotational symmetry below a characteristic temperature, is an intensely investigated contemporary subject. Nematicity is closely connected to the structural…
Magnetoresistance loops under in-plane applied field were measured on perpendicularly magnetized magnetic tunnel junction (pMTJ) pillars with nominal diameters ranging from 50 to 150 nm. By fitting the hard-axis magnetoresistance loops to…
The magnetic, transport and optical properties of EuFe$_2$As$_2$ single crystals have been investigated parallel and perpendicular to the $ab$-plane. The anisotropy $\rho_c/\rho_{ab}\approx 8$ depends only slightly on temperature. In both…
The unusual temperature dependence of the resistivity and its in-plane anisotropy observed in the Fe-based superconducting materials, particularly Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$, has been a longstanding puzzle. Here we consider the effect…
The hallmark of nematic order in iron-based superconductors is a resistivity anisotropy but it is unclear to which extent quasiparticle dispersions, lifetimes and coherence contribute. While the lifted degeneracy of the Fe $d_{xz}$ and…
We examine the magnetic phase diagram of iron pnictides using a five band model. For the intermediate values of the interaction expected to hold in the iron pnictides, we find a metallic low moment state characterized by antiparallel…
We study the structural and magnetic orders in electron-doped BaFe2-xNixAs2 by high-resolution synchrotron X-ray and neutron scatterings. Upon Ni-doping x, the nearly simultaneous tetragonal-to-orthorhombic structural T_s and…
The anisotropy in the electronic structure of the inherently nanolaminated ternary phase Cr$_{2}$GeC is investigated by bulk-sensitive and element selective soft x-ray absorption/emission spectroscopy. The angle-resolved absorption/emission…
Understanding the nature of the electronic nematic phase in iron pnictide superconductors is important for elucidating its impact on high-temperature superconductivity. Here we use transport and inelastic neutron scattering to study spin…