发表机构
Shiv Nadar Institution of Eminence (SNIoE)（Shiv Nadar卓越机构）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文研究三维节线半金属中倾斜与能隙对等离激元模式的影响，通过随机相位近似计算响应函数，揭示部分能隙区域及分数幂修正，系统比较不同倾斜方向下的色散与各向异性。
AI 中文摘要
我们研究了三维节线半金属中的等离激元模式，同时考虑了无能隙的$\mathcal{PT}$对称节线环（PTNR）及其有能隙对应物（GNR）。在低掺杂区间内，线性化哈密顿量有效，我们计算了无相互作用密度-密度响应函数、Drude权重以及随机相位近似下的等离激元色散关系。我们处理了无倾斜构型以及沿$k_x$的面内倾斜和沿$k_z$的轴向倾斜。对于面内倾斜的GNR，足够强的倾斜或足够小的化学势会将环的一部分推入部分能隙区域。在那里，只有部分费米面存活。我们在此区域的两个极限下获得了闭式结果：小倾斜和小能隙。小能隙极限产生了对Drude权重和等离激元频率的分数幂修正。对于轴向倾斜的GNR，部分能隙窗口具有双值局部费米面，我们为其获得了态密度和Drude权重的闭式表达式。我们分析了倾斜和质量能隙如何影响等离激元色散以及轴向与面内方向之间的各向异性。我们的结果为无能隙与有能隙情况之间以及不同倾斜方向之间提供了系统的比较。
英文摘要
We study collective charge excitations in three-dimensional $\mathcal{PT}$-symmetric nodal-ring semimetals (PTNRs) and their gapped counterparts (GNRs) in the presence of band tilt, together with Weyl semimetals (WSMs). Within a low-energy two-band description, we consider untilted systems as well as in-plane and axial tilts. Using the random-phase approximation, we obtain the density of states, Drude weights, dielectric functions, and plasmon dispersions at low doping and in the intrinsic limit. The mass gap and the two inequivalent tilt directions generate distinct Fermi-surface topologies and thereby control the formation and damping of plasmons. By comparing the collective modes with the particle-hole continuum, we identify the regimes in which plasmons remain well defined. We also calculate the response of untilted and tilted WSMs and contrast it with that of PTNRs and GNRs. The two classes of semimetals differ in the carrier-density dependence and isotropy of the plasmon frequency as well as in interband screening and their response to tilt. These differences reflect their distinct Fermi-surface geometries and interband structures. Our results establish how mass and tilt govern collective charge dynamics through their interplay with intraband spectral weight and interband particle-hole excitations.
Commentscompanion paper of arXiv:2610.03188; substantially revised and expanded
