We report on an infrared study on the undoped compound BaFe2As2 as a function of both pressure (up to about 10 GPa) at three temperatures (300, 160, and 110 K). The evolution with pressure and temperature of the optical conductivity shows that, by increasing pressure, the mid-infrared absorptions associated with magnetic order are lowered while the Drude term increases, indicating the evolution towards a conventional metallic state. We evaluate the spectral weight dependence on pressure comparing it to that previously found upon doping. The whole optical results indicate that lattice modifications can not be recognized as the only parameter determining the low-energy electrodynamics in these compounds.
The pressure dependence of electron-phonon coupling in the organic superconductor $κ$-(BEDT-TTF)$_{2}$Cu(SCN)$_{2}$: A comparison of high pressure infrared reflectivity and Raman scattering experiments
Electrodynamics near the Metal-to-Insulator Transition in V3O5
本文用红外光谱研究了V_3O_5单晶在温度（T）和压力（P）下引起的金属-绝缘体相变（MIT）附近的电动力学。的T-和P-依赖性的光学电导率可以解释在极化的情况下。在环境温度T和P下的绝缘相对应于强局域化的小极化子。同时，在环境压力下的T-诱导的金属相是与极化子的液体表现出非相干直流输运，在P-诱导的金属相在室温T强局域极化子共存的部分离域的。的电子光谱重量几乎恢复，在T和P诱导的金属化过程中，在1 eV的能量尺度上，从而支持电子晶格相互作用中的V3 O 5金属-绝缘体转变的关键作用。
The pressure dependence of many-body interactions in the organic superconductor $κ$-(BEDT-TTF)$_{2}$Cu(SCN)$_{2}$: A comparison of high pressure infrared reflectivity and Raman scattering experiments
We present THz measurements of thin films of mixed-valent YbAl$_3$ and its structural analogue LuAl$_3$. Combined with traditional Fourier transform infrared (FTIR) spectroscopy, the extended Drude formalism is utilized to study the low-frequency transport of these materials. We find that LuAl$_3$ demonstrates conventional Drude transport whereas at low temperatures YbAl$_3$ demonstrates a sharply renormalized Drude peak and a mid-infrared (MIR) peak in the conductivity, indicative of the formation of a heavy Fermi liquid. In YbAl$_3$ the extended Drude framework shows a consistency of the sca…
Lattice vibrations of the charge-transfer salt $κ$-(BEDT-TTF)$_2$Cu$_2$(CN)$_{3}$: novel interpretation of the electrodynamic response in a spin-liquid compound
二聚体Mott绝缘体$κ$ -（BEDT-TTF）$_2$ Cu $_2$（CN）$_3$具有不寻常的电动力学性质。电子基态和分子和晶格振动的数值研究揭示了耦合到BEDT-TTF分子的Cu $_2$（CN）$_3^-$阴离子网络的重要性：铜的三重氰化物配位和阴离子结构中的键异构性导致对称性、挫折、无序和域形成的损失。我们的研究结果一致地解释了温度和偏振相关的THz和红外测量，加强了对介电性质的理解，并对量子自旋液体状态具有重要意义，这应该超越二维纯电子模型。
We examine transport in a holographic model which describes, through a nonlinear gauge field sector, generic nonlinear interactions between the charge carriers. Scaling exponents are introduced by using geometries which are nonrelativistic and hyperscaling-violating in the infrared. In the dilute charge limit in which the gauge field sector does not backreact on the geometry, a particularly simple nonlinear theory reproduces the anomalous temperature dependence of the resistivity and Hall angle of the cuprate strange metals, $R \sim T$ and $\cotΘ_H \sim T^2$ while also allowing for a linear en…
