论文标题
部分可观测时空混沌系统的无模型预测
Anisotropic Behavior of the Thermoelectric Power and the Thermal Conductivity in a Unidirectional Lateral Superlattice: A Typical Anisotropic System Exhibiting Two Distinct Nernst Coefficients
论文作者
论文摘要
我们已经计算了热电电导率张量$ \ varepsilon_ {ij} $和导热量张量$λ_{ij} $的单向侧向超级级别（ulsl）（ulsl）（$ i，j = x，y $，带有$ x $ -Axiss and and Serige and a in Ulss and as the uls and as the uls and in ulsal and in ulsal and in ulsal and in ulsal ass。在文献中使用电导率张量$σ_{ij} $的渐近分析公式采用的矩，在低磁场有效的文献中，占据了大量Landau水平的低磁场。通过产生的分析表达式，我们澄清了Mott公式（Wiedemann-Franz Law）的条件，适用于$ \ varepsilon_ {ij} $（$λ_{ij {ij} $）。我们进一步介绍了相当性振荡$δ\ varepsilon_ {ij} $，$δλ_{ij} $，$Δκ__{ij {ij {ij} $，以及$ΔS_{ij {ij {ij} $ in $ \ varepsilon_ in $ \ varepsilon_ {张量$κ_{ij} $和热电张量$ s_ {ij} $，使用典型的参数计算用于用GAAS/ALGAAS二维电子（2DEG）制造的ULSL。 $ΔS_{ij} $的显着特征是（i）各向异性行为（$ΔS_{xx}} \neΔS_{yy} $）和（ii）$ xy $组件的主导地位（$ xy $ componge）优于其他组件（$ | ex_ | eu | ex_ {xy} {xy} | \ gggg |Δ |ΔS_{xx} |，|ΔS_{yy} | $）。后者清楚地表明，在各向异性系统中，两个Nernst系数，$ s_ {xy} $和$ s_ {yx} $可以完全不同。 （i）和（ii）均与先前的理论有所不同，并且由于GAAS/藻类2DEG的小角度散射特征而构成了阻尼因子，尚未考虑到$ΔS_{IJ} $。
We have calculated the thermoelectric conductivity tensor $\varepsilon_{ij}$ and the thermal conductivity tensor $λ_{ij}$ of a unidirectional lateral superlattice (ULSL) ($i,j = x,y$, with the $x$-axis aligned to the principal axis of the ULSL), %, given as the first- and the second-order moments, employing based on the asymptotic analytic formulas of the electrical conductivity tensor $σ_{ij}$ in the literature valid at low magnetic fields where large numbers of Landau levels are occupied. With the resulting analytic expressions, we clarify the conditions for the Mott formula (Wiedemann-Franz law) to be applicable with high precision to $\varepsilon_{ij}$ ($λ_{ij}$). We further present plots of the commensurability oscillations $δ\varepsilon_{ij}$, $δλ_{ij}$, $δκ_{ij}$, and $δS_{ij}$ in $\varepsilon_{ij}$, $λ_{ij}$, (an alternative, more standard definition of) the thermal conductivity tensor $κ_{ij}$, and the thermopower tensor $S_{ij}$, calculated using typical parameters for a ULSL fabricated from a GaAs/AlGaAs two-dimensional electron gas (2DEG). Notable features of the $δS_{ij}$ are (i) anisotropic behavior ($δS_{xx} \ne δS_{yy}$) and (ii) the dominance of the $xy$ component over the other components ($|δS_{xy}| \gg |δS_{yx}|, |δS_{xx}|, |δS_{yy}|$). The latter clearly indicates that the two Nernst coefficients, $S_{xy}$ and $S_{yx}$, can be totally different from each other in an anisotropic system. Both (i) and (ii) are at variance with the previous theory and are attributable to the inclusion of a damping factor due to the small-angle scattering characteristic of GaAs/AlGaAs 2DEGs, which have not been taken into consideration in $δS_{ij}$ thus far.
