论文标题
电子 - 音波耦合的电子依赖性是yni $ _2 $ b $ _2 $ c的戏剧性声子重量化的基础
Electron-momentum dependence of electron-phonon coupling underlies dramatic phonon renormalization in YNi$_2$B$_2$C
论文作者
论文摘要
电子 - 音波耦合，即通过电子对晶格振动的散射，反之亦然，在固体中无处不在，可能导致出现的基态，例如超导性和电荷密度波顺序。在费米表面附近的电子子与电子的强烈耦合，这会降低声子寿命并在散射实验中拓宽声子峰，这通常与费米表面嵌套有关。在这里，我们表明在没有费米表面嵌套和晶格非谐度的情况下，强烈的声子扩大，如果电子偶联对电子偶联的特定值k，k，k。我们使用非弹性中子散射，软X射线角度分辨光谱光谱测量值以及AB-Initio晶格动力学和电子带结构计算，以证明在高度各向异性的四方电子phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phonon-Phone-Phone-Phone-Phone-Phone-Phone-Phone-Phone-Phone-Phone-Phonepodor yni yni $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ c。这种新方案可能适用于多种化合物。
Electron-phonon coupling, i.e., the scattering of lattice vibrations by electrons and vice versa, is ubiquitous in solids and can lead to emergent ground states such as superconductivity and charge-density wave order. Strong coupling of phonons to electrons near the Fermi surface, which reduces the phonon lifetimes and broadens the phonon peaks in scattering experiments, is often associated with Fermi surface nesting. Here, we show that strong phonon broadening can occur in the absence of both Fermi surface nesting and lattice anharmonicity, if electron-phonon coupling is strongly enhanced for specific values of electron-momentum, k. We use inelastic neutron scattering, soft x-ray angle-resolved photoemission spectroscopy measurements and ab-initio lattice dynamical and electronic band structure calculations to demonstrate this scenario in the highly anisotropic tetragonal electron-phonon superconductor YNi$_2$B$_2$C. This new scenario likely applies to a wide range of compounds.
