自旋轨道耦合对各向异性导体态密度的电子关联修正的影响
Impact of spin-orbit coupling on electron correlation corrections to the density of states in anisotropic conductors
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中文总结 AI 辅助
该研究探讨了在受Rashba和Dresselhaus自旋轨道耦合约束的强各向异性二维导体中，Altshuler-Aronov型相互作用对态密度的修正，发现自旋轨道耦合可调控关联修正，存在临界强度抵消修正并反转符号，为相关效应提供光谱特征。
中文摘要 AI 辅助
我们研究了在存在共同作用的Rashba和Dresselhaus自旋轨道耦合（SOC）且被限制在纵向方向的情况下，具有开放费米面（FS）和弱无序的强各向异性二维导体中，Altshuler-Aronov型相互作用对单粒子态密度（DOS）的修正。低能带由两个在横向弱隧穿耦合的扭曲片构成；SOC将这些片分裂为具有固定自旋轴的螺旋分支。我们在Matsubara空间中，计算了扩散通道中包含动态屏蔽库仑相互作用和杂质梯子的交换贡献。所得DOS异常表现出由横向耦合标度ε_c控制的维度交叉。在费米能级附近（|ε-ε_F|<ε_c），系统表现为二维行为，具有对数形式的DOS凹陷，其幅度被本征SOC增强。在远离费米能级处（|ε-ε_F|>ε_c），系统表现为准一维行为，具有更尖锐的平方根奇点，其幅度被SOC显著增强。值得注意的是，我们确定了一个临界SOC强度，在此强度下，这些自旋轨道效应恰好抵消电子关联修正，完美恢复未受扰动的态密度。此外，将SOC增加超过该临界点会完全反转异常的符号，产生正的DOS修正。这种符号反转从根本上改变了能量依赖性，使得在ε_F+ε_c以上的能量处，正修正随能量增加而衰减为更小的值，这与标准负修正相反。这种对比趋势为SOC调制的关联效应提供了独特的光谱特征。
英文摘要
We study Altshuler-Aronov-type interaction corrections to the single-particle density of states (DOS) in a strongly anisotropic 2D conductor with an open Fermi surface (FS) and weak disorder, in the presence of coexisting Rashba and Dresselhaus spin-orbit couplings (SOCs) constrained to the longitudinal direction. The low-energy band consists of two warped sheets weakly tunnel-coupled transversely; SOC splits the sheets into helicity branches with a fixed spin axis. Working in a Matsubara space, we compute the exchange contribution in the diffusion channel with dynamically screened Coulomb interaction and an impurity ladder. The resulting DOS anomaly exhibits a dimensional crossover governed by the transverse coupling scale $\varepsilon_c$. Close to the Fermi level ($|\varepsilon-\varepsilon_F|<\varepsilon_c$), the system behaves two-dimensionally, featuring a logarithmic DOS dip whose magnitude is enhanced by intrinsic SOCs. Further from the Fermi level ($|\varepsilon-\varepsilon_F|\!>\!\varepsilon_c$), the system behaves quasi-one-dimensionally, featuring a sharper square-root singularity whose amplitude is remarkably enhanced by the SOCs. Notably, we identify a critical SOC strength at which these spin-orbit effects exactly cancel the electron-correlation correction, perfectly restoring the unperturbed density of states. Furthermore, increasing the SOC beyond this critical point inverts the sign of the anomaly entirely, yielding a positive DOS correction. This sign reversal fundamentally alters the energy dependence, such that at energies beyond $\varepsilon_F + \varepsilon_c$, the positive correction decays to smaller values as energy increases, opposite to the standard negative correction. This contrasting trend provides a distinct spectroscopic signature of SOC-modulated correlation effects.
