Anderson模型失平衡的GW方法：I-V特性中的库仑阻塞和假滞后
GW approach to Anderson model out of equilibrium: Coulomb blockade and false hysteresis in the I-V characteristics
摘要：
在强电子-电子相互作用机制下，采用$GW$近似，研究了单个杂质与两个引线耦合的Anderson模型，该模型是杂质能级相对于引线中化学势的函数。我们采用非平衡格林函数技术来计算电子的自能，自旋密度和电流作为跨结偏压的函数。此外，我们开发了一个表达式的变化的期望值的系统的能量，结果当杂质耦合到引线，包括库仑相互作用通过电子自能在该区域的结的作用。在GW近似下计算的电流-电压特性表现出库仑阻塞。根据栅极电压和外加偏压，我们发现，可以有一个以上的稳态解的系统，这可能会引起滞后的I-V特性。我们表明，滞后是一个工件的$GW$近似，将无法生存，如果量子涨落超过$GW$近似包括在内。
英文摘要：
The Anderson model for a single impurity coupled to two leads is studied using the $GW$ approximation in the strong electron-electron interaction regime as a function of the alignment of the impurity level relative to the chemical potentials in the leads. We employ a non-equilibrium Green's function technique to calculate the electron self-energy, the spin density and the current as a function of bias across the junction. In addition we develop an expression for the change in the expectation value of the energy of the system that results when the impurity is coupled to the leads, including the role of Coulomb interactions through the electron self energy in the region of the junction. The current-voltage characteristics calculated within the GW approximation exhibit Coulomb blockade. Depending on the gate voltage and applied bias, we find that there can be more than one steady-state solution for the system, which may give rise to a hysteresis in the I-V characteristics. We show that the hysteresis is an artifact of the $GW$ approximation and would not survive if quantum fluctuations beyond the $GW$ approximation are included.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
