Prominent 5d-orbital contribution to the conduction electrons in gold

金衬底上单层CrSBr的两个导带

The two conduction bands of monolayer CrSBr on Au

本研究通过角分辨光电子能谱发现，超平金衬底上的单层CrSBr因电荷转移填充导带且带隙减小，还出现X点劈裂的两个导带，揭示衬底可破缺滑移镜面对称性、重塑二维材料能带拓扑。

Collective excitations from composite orders in Kondo lattice with non-Kramers doublets

Goldstone modes emerge associated with spontaneous breakdown of the continuous symmetry in the two-channel Kondo lattice, which describes strongly correlated f-electron systems with a non-Kramers doublet at each site. This paper derives the spectra of these collective modes by the equation of motion method together with the random phase approximation. The diagonal composite order breaks the SU(2) channel symmetry, and the symmetry-restoring collective mode couples with magnetic field. On the other hand, the off-diagonal or superconducting composite order breaks the gauge symmetry of conduction…

Prominent electron-hole asymmetry in thermoelectric transport of LaCoO$_3$

We have measured the electrical resistivity and the thermopower of the electron-doped perovskite cobaltites LaCo$_{1-y}$Te$_y$O$_3$. In contrast to the hole-doped systems such as metallic ferromagnets La$_{1-x}M_x$CoO$_3$ ($M$ = Ca, Sr, Ba), the electron-doped samples show an insulating behavior even in a heavily doped range due to a spin-state blockade mechanism that an electron hopping from high-spin Co$^{2+}$ to low-spin Co$^{3+}$ site is energetically suppressed. We find that, despite the electron doping, the thermopower shows relatively large positive values above $y=0.05$, strikingly dis…

New Model System for a One-Dimensional Electron Liquid: Self-Organized Atomic Gold Chains on Ge(001)

Unique electronic properties of self-organized Au atom chains on Ge(001) in novel c(8x2) long-range order are revealed by scanning tunneling microscopy. Along the nanowires an exceptionally narrow conduction path exists which is virtually decoupled from the substrate. It is laterally confined to the ultimate limit of single atom dimension, and is strictly separated from its neighbors, as not previously reported. The resulting tunneling conductivity shows a dramatic inhomogeneity of two orders of magnitude. The atom chains thus represent an outstandingly close approach to a one-dimensional elec…

Kondo screening in a charge-insulating spinon metal

The Kondo effect, an eminent manifestation of many-body physics in condensed matter, is traditionally explained as exchange scattering of conduction electrons on a spinful impurity in a metal. The resulting screening of the impurity's local moment by the electron Fermi sea is characterized by a Kondo temperature $T_K$, below which the system enters a non-perturbative strongly-coupled regime. In recent years, this effect has found its realizations beyond the bulk-metal paradigm in many other itinerant-electron systems, such as quantum dots in semiconductor heterostructures and in nanomaterials,…

在具有纳米界面的结晶金中实现超强电子-声子耦合与非经典电子输运

Engineering ultra-strong electron-phonon coupling and nonclassical electron transport in crystalline gold with nanoscale interfaces

通过在结晶金壳层中嵌入超小银纳米颗粒，实现电子-声子耦合强度λ高达约20的显著增强，使电阻率偏离线性并趋近Mott-Ioffe-Regel饱和，从而首次实验触及非经典金属输运区域。