Kumar Abhishek, Yudson Vladimir I, Maslov Dmitrii L
University of Florida, Gainesville, Florida 32611, USA.
Laboratory for Condensed Matter Physics, National Research University "Higher School of Economics" 20 Myasnitskaya Street, Moscow 101000, Russia.
Phys Rev Lett. 2021 Feb 19;126(7):076601. doi: 10.1103/PhysRevLett.126.076601.
Charge transport in doped quantum paraelectrics (QPs) presents a number of puzzles, including a pronounced T^{2} regime in the resistivity. We analyze charge transport in a QP within a model of electrons coupled to a soft transverse optical (TO) mode via a two-phonon mechanism. For T above the soft-mode frequency but below some characteristic scale (E_{0}), the resistivity scales with the occupation number of phonons squared, i.e., as T^{2}. The T^{2} scattering rate does not depend on the carrier number density and is not affected by a crossover between degenerate and nondegenerate regimes, in agreement with the experiment. Temperatures higher than E_{0} correspond to a nonquasiparticle regime, which we analyze by mapping the Dyson equation onto a problem of supersymmetric quantum mechanics. The combination of scattering by two TO phonons and by a longitudinal optical mode explains the data quite well.
掺杂量子顺电体（QP）中的电荷输运存在许多谜题，包括电阻率中明显的(T^{2})规律。我们在一个通过双声子机制将电子与软横向光学（TO）模式耦合的模型中分析QP中的电荷输运。对于高于软模式频率但低于某个特征尺度（(E_{0})）的温度(T)，电阻率与声子占据数的平方成正比，即与(T^{2})成正比。(T^{2})散射率不依赖于载流子数密度，并且不受简并和非简并区域之间交叉的影响，这与实验结果一致。高于(E_{0})的温度对应于非准粒子区域，我们通过将戴森方程映射到超对称量子力学问题来分析该区域。由两个TO声子和一个纵向光学模式引起的散射组合很好地解释了这些数据。
