Using the self-consistent Hartree-Fock method, we calculate the persistent current of weakly-interacting spinless electrons in a one-dimensional ring containing a single delta-barrier. We find that the persistent current decays with the system length (L) asymptotically like $I \propto L^{-1-α}$, where $α> 0$ is the power depending only on the electron-electron interaction. We also simulate tunneling of the weakly-interacting one-dimensional electron gas through a single delta-barrier in a finite wire biased by contacts. We find that the Landauer conductance decays with the system length asymptotically like $L^{-2α}$. The power laws $L^{-1-α}$ and $L^{-2α}$ have so far been observed only in correlated models. Their existence in the Hartree-Fock model is thus surprising.
We study the mechanical actions affecting close scatterers immersed in a coherent fermionic fluid. Using a scattering field theory, we theoretically analyse the single-scatterer and the two-scatterer case. Concerning the single-scatterer case, we find that a net force affects the scatterer dynamics only in non-equilibrium condition, i.e. imposing the presence of a non-vanishing particle current flowing through the system. The force fluctuation (variance) is instead not negligible both in equilibrium and in non-equilibrium conditions. Concerning the two-scatterer case, an attractive fluid-media…
Enhanced quantum oscillatory magnetization and non-equilibrium currents in an interacting two-dimensional electron system in MgZnO/ZnO with repulsive scatterers
Monte-Carlo simulation of the coherent backscattering of electrons in a ballistic system
我们研究了人为散射体引起的弹道机制中的弱局域化效应。离开这些散射体的电子的镜面反射导致后向散射轨迹,后向散射轨迹干扰它们的时间反转路径,导致对电阻的弱局部化校正。使用半经典理论,我们计算由于这些背散射轨迹的电阻的变化。我们发现,为了解释Katine等人[Superlattices and Microstructures 20,337(1996)]的实验结果,包含散射体的精确形状是非常重要的。
We have utilized the finite-difference approach to explore electron-tunneling properties in gapped graphene through various electrostatic-potential barriers changing from Gaussian to a triangular envelope function in comparison with a square potential barrier. Transmission coefficient is calculated numerically for each case and applied to corresponding tunneling conductance. It is well known that Klein tunneling in graphene will be greatly reduced in a gapped graphene. Our results further demonstrate that such a decrease of transmission can be significantly enhanced for spatially-modulated pot…
In this work we develop an experimental procedure to interrogate the single- and multiphoton scattering matrices of an unknown quantum system interacting with propagating photons. Our proposal requires coherent state laser or microwave inputs and homodyne detection at the scatterer's output, and provides simultaneous information about multiple ---elastic and inelastic--- segments of the scattering matrix. The method is resilient to detector noise and its errors can be made arbitrarily small by combining experiments at various laser powers. Finally, we show that the tomography of scattering has…
The distribution of electron waiting times is useful to characterize quantum transport in mesoscopic structures. Here we consider a generic quantum-coherent conductor consisting of a mesoscopic scatterer in a two-terminal setup. We extend earlier results for single-channel conductors to setups with several (possibly spin-degenerate) conduction channels and we discuss the effect of a finite electronic temperature. We present detailed investigations of the electron waiting times in a quantum point contact as well as in two mesoscopic interferometers with energy-dependent transmissions: a Fabry-P…
Coulomb Effects and Electron Transport Through a Coherent Conductor
我们分析了在库仑相互作用存在下,电子输运通过相对较短的相干导体。我们考虑到外部环境的影响,这样的导体的电流-电压特性进行评估。在我们的模型中,在大电导和低$T$的电导被抑制的一个通用的因素,这只取决于类型的导体。我们还认为,在T=0的系统"散射体+分流“可以是绝缘体或金属取决于它的总电阻是大于或小于$R_Q=h/e^2\approx 25.8$ k $Ω$。在金属相中,库仑能隙被量子涨落完全抑制。
When combining lumped mesoscopic electronic components to form a circuit, quantum fluctuations of electrical quantities lead to a non-linear electromagnetic interaction between the components that is not generally understood. The Landauer-Büttiker formalism that is frequently used to describe non-interacting coherent mesoscopic components is not directly suited to describe such circuits since it assumes perfect voltage bias, i.e. the absence of fluctuations. Here, we show that for short coherent conductors of arbitrary transmission, the Landauer-Büttiker formalism can be extended to take into …
We present diagrammatic transport theory including self-consistent nonlinear enhancement and dissipation in the multiple scattering regime. Our model of Vollhardt-Wölfle transport of photons is fit-parameter-free and raises the claim that the results hold up to the closest packed volume of randomly arranged ZnO Mie scatterers. We find that a symmetry breaking caused by dissipative effects of a lossy underlying substrate leads to qualitatively different physics of coherence and lasing in granular amplifying media. According to our results, confined and extended mode and their laser thresholds c…