We investigate the low-temperature thermoelectric properties of three-dimensional nodal-line semimetals within the semiclassical Boltzmann formalism. Considering short-range interaction between electrons and scattering agents, we calculate the anisotropic relaxation times and then obtain the charge conductivity and thermopower along the radial and the axial directions with respect to the nodal-line plane. Increasing the carrier concentration, a sharp change in the thermopower signals topological transition in the shape of the Fermi surface from a torus into an ellipsoid. An adequate treatment of the energy and direction dependence of the relaxation time is necessary for the observation of the topological transition of the Fermi surface in the thermoelectric properties.

中文翻译：

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节点线半金属的热电响应：探查费米表面拓扑

我们研究了半经典玻尔兹曼形式主义中的三维节点线半金属的低温热电性质。考虑到电子和散射剂之间的短程相互作用，我们计算了各向异性弛豫时间，然后获得了相对于节点线平面沿径向和轴向的电荷传导率和热功率。随着载流子浓度的增加，热电势的急剧变化表明费米表面的形状从圆环到椭圆形发生拓扑转变。为了观察费米表面在热电特性中的拓扑转变，必须对弛豫时间的能量和方向相关性进行适当处理。