AI 中文总结
该研究通过动力学平均场理论分析两带哈伯德模型，发现洪德耦合产生的局域自旋激发是轨道选择莫特相中准粒子崩溃的基本机制，移除洪德耦合的相关分量可恢复准粒子相干行为。
AI 中文摘要
轨道选择莫特相（OSMP）通常被描述为有效解耦轨道内局域电子与巡游电子的共存态，但准粒子崩溃的新证据表明存在超出该图像的物理现象，其微观起源仍未知。针对两带哈伯德模型，采用动力学平均场理论，研究发现洪德耦合的自旋翻转和伊辛型分量会产生局域自旋激发（LSEs）；这些LSEs耦合不同轨道间的电子，重整化准粒子寿命与结合能，进而破坏OSMP中定义明确的准粒子。移除洪德耦合的这两个分量后，准粒子相干行为得以恢复，且两带电荷动力学完全解耦。研究结果明确，电子与LSEs的耦合是驱动OSMP内准粒子崩溃的基本机制。
英文摘要
The orbital-selective Mott phase (OSMP) is commonly described as a coexistence of localized and itinerant electrons within effectively decoupled orbitals, but emerging evidence for quasiparticle breakdown points to physics beyond this picture, whose microscopic origin remains unknown. Using dynamical mean-field theory for the two-band Hubbard model, we show that the spin-flip and Ising-type components of Hund's coupling generate local spin excitations (LSEs). These LSEs couple electrons between different orbitals, renormalize quasiparticle lifetimes and binding energies, and thereby destroy well-defined quasiparticles in the OSMP. Removing these two components of Hund's coupling restores coherent quasiparticle behavior and fully decouples the charge dynamics of the two bands. Our results therefore identify electronic coupling to LSEs as the fundamental mechanism driving quasiparticle breakdown within the OSMP.
Comments6 pages, 3 figures
