弹性、准弹性及超弹性电子散射与热晶格畸变在完美晶体中的关系
Elastic, Quasielastic, and Superelastic Electron Scattering from Thermal Lattice Distortions in Perfect Crystals
AI总结：
研究揭示了完美晶体中电子与晶格相互作用的弹性散射机制，提出了弹性、准弹性和超弹性过程，为理解清洁晶体中的动量弛豫提供了新视角。
摘要：
在标准的电子输运理论中，完美、无缺陷晶体中的动量弛豫通常与声子的产生或湮灭相关。本文重新考虑了有限、孤立晶体中的这一问题，保留晶格中心质量（反冲）自由度，并强制总机械动量和离散晶体伪动量的守恒。从电子-晶格相互作用的密度-密度形式出发，证明了完美晶体内部电子可通过弹性动量转移通道实现动量守恒，无需声子激发。这些弹性通道可为动量弛豫提供主要贡献。进一步识别了混合准弹性和超弹性过程，其中声子占据数变化但不完全解释电子动量转移。弹性通道源于标准微观哈密顿量，无需额外的杂质或缺陷。所得框架为清洁晶体中的动量弛豫提供了互补的微观视角，并与弱局域化、量子振荡、超声衰减和观察到的动量与能量弛豫时间分离等实验现象一致。
英文摘要：
In standard treatments of electron transport, momentum relaxation in a perfect, defect-free crystal is linked with phonon creation or annihilation. In this work, we reconsider this problem for a finite, isolated crystal, retaining the lattice center-of-mass (recoil) degree of freedom and enforcing conservation of total mechanical momentum together with discrete crystal pseudomomentum. Starting from the density-density form of the electron-lattice interaction, we show that an electron in the interior of a perfect crystal admits elastic momentum-transfer channels in which total momentum is conserved by recoil of the lattice background without phonon excitation. These elastic channels can provide the leading contribution to momentum relaxation. We further identify mixed quasi-elastic and superelastic processes in which phonon occupations change but do not account entirely for the electron's momentum transfer. The elastic channels arise within the standard microscopic Hamiltonian and do not require additional disorder or defects. The resulting framework provides a complementary microscopic perspective on momentum relaxation in clean crystals and is consistent with experimental phenomena such as weak localization, quantum oscillations, ultrasonic attenuation, and the observed separation of momentum and energy relaxation times.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
