We consider the effect of disorder on the themopower in quantum Hall systems. For a sample in the Corbino geometry, where dissipative currents are not carried by edge states, we find that thermopower behaves at high temperatures like a system with a gap and has a maximum which increases as the temperature is reduced. At lower temperatures this maximum reduces as a function of temperature as a result of tunneling across saddle points in the background potential. Our model assumes that the mean saddle point height varies linearly with the deviation in filling factor from the quantized value. We test this hypothesis against observations for the dissipative electrical conductance as a function of temperature and field and find good agreement with experiment around the minimum.
The thermopower as a fingerprint of the Kondo breakdown quantum critical point
我们提出，热电势区分两个竞争的情况下，量子相变在重费米子：自旋密度波（SDW）理论和击穿的近藤效应。在近藤崩溃的情况下，塞贝克系数原来从温度标度$E^{*}$，与费米表面重构的量子涨落崩溃。这一特征与SDW理论的物理性质有着根本的不同，在SDW理论中，费米面不会发生重构，这一特征可以被认为是近藤击穿理论的标志。我们测试这些想法，对YbRh $_2$ Si $_2$的实验结果。
Unconventional Metallicity and Giant Thermopower in a Strongly Interacting Two Dimensional Electron System
我们目前的热和电输运测量的低密度（10 $^{14}$ m $^{-2}$），介观二维电子系统（2DES）在GaAs/AlGaAs异质结在亚开尔文温度。我们发现，即使在假定的强烈本地化制度，其中系统的电阻率是两个数量级大于量子电阻$h/e^2$，热电势随温度线性下降，表明金属性。值得注意的是，热电势的大小超过预测值在非相互作用的金属2DES在类似的载流子密度超过两个数量级。我们的结果表明，一个新的量子态，并可能是一种新的类巡回准粒子在稀释的2DES在低温下，库仑相互作用起着关键作用。
Nernst Effect as a Probe of Local Kondo Scattering in Heavy Fermions
CeCu $_2$ Si $_2$和Ce $_{0.8}$ La $_{0.2}$ Cu $_2$ Si $_2$在$T$ = 2 K和300 K之间观察到大的、强烈温度依赖性的能斯特系数$ν$。增强的$ν(T)$由现场近藤（传导电子$-4f$电子）散射速率的不对称性决定。考虑到测得的霍尔迁移率，$μ_H$，这些系统的高度不寻常的热电势，$S$，可以半定量地描述为$S(T)$ $=$ $-$ $ν(T)/μ_H(T)$，这明确表明，热电势起源于本地近藤散射过程在很宽的温度范围内从远高于低于相干温度（$\approx$ 20 K的CeCu $_2$ Si $_2$）。我们的结果表明，能斯特效应可以作为一个适当的探针的本地电荷载流子散射。这对探索适合于潜在应用的相关材料中的非常规热电势增强具有重要意义。
We consider non-Fermi liquids in which the inelastic scattering rate has an intrinsic particle-hole asymmetry and obeys $ω/T$ scaling. We show that, in contrast to Fermi liquids, this asymmetry influences the low-temperature behaviour of the thermopower even in the presence of impurity scattering. Implications for the unconventional sign and temperature dependence of the thermopower in cuprates in the strange metal (Planckian) regime are emphasized.
Magnetic field dependence of the thermopower of Kondo-correlated quantum dots: Comparison with experiment
近藤效应在强关联量子点电导中的特征在实验和理论上都得到了很好的理解，而热电势中的特征则是最近感兴趣的主题。在这里，我们推广了理论工作[T. A. Costi，Phys. Rev. B { \bf 100}，161106（R）（2019）]，并进行计算以解决最近关于近藤相关量子点的场相关热电响应的实验[A. Svilans { \em et al.，}物理修订版信函{ \bf 121}，206801（2018）]。在近藤体系中，除了在温度$T_1(B)$和$T_2(B)$（也存在于$B=0$中）下热电势的符号变化之外，还发现了另外的符号变化[T. A. Costi，Phys. Rev. B { \bf 100}，161106（R）（2019）]，在温度$T_0(B)<T_1(B)<T_2(B)$下，对于超过栅极电压相关值$B_0$的场，其中$B_0$与近藤共振分裂的场$B_c$相当，但大于近藤共振分裂的场。我们描述了近藤引起的符号变化的热电势在温度$T_0(B),T_1(B)$和$T_2(B)$与磁场和门电压从近藤制度的混合价和空轨道制度的演变。通过对上述量进行详细的NRG计算，我们讨论了A. Svilans { \em et al.，}物理修订信函{ \bf 121}，206801（2018），测量了表现出近藤效应的InAs量子点的场依赖性热电响应，发现测量的场依赖性和温度依赖性热…
Interacting Tomonaga-Lüttinger liquid with impurity for interaction constant $K = 1/2$: Thermopower investigation, entropy variation and heat capacity densities associated with thermoelectric particle transport
University of Bouira（布依拉大学）；Higher Normal School of Bouzareah, University of Bouira（布扎雷亚高等师范学院，布依拉大学）
A detailed investigation of the non-equilibrium steady-state electric and thermoelectric transport properties of a quantum dot coupled to the normal metallic and s-wave superconducting reservoirs (N-QD-S) are provided within the Coulomb blockade regime. Using non-equilibrium Keldysh Green's function formalism, initially, various model parameter dependence of thermoelectric transport properties are analysed within the linear response regime. It is observed that the single-particle tunnelling close to the superconducting gap edge can generate a relatively large thermopower and figure of merit. M…
