Inelastic Cotunneling Current and Shot Noise of an Interacting
Quantum Dot with Ferromagnetic Correlations |
| |
Authors: | DONG Bing LEI Xiao-Lin Norman JM Horing |
| |
Institution: | 1. Department of Physics, Shanghai Jiao Tong University, Shanghai 200030, China
;2. Department of Physics and Engineering Physics, Stevens
Institute of Technology, Hoboken, New Jersey 07030, USA |
| |
Abstract: | We explore inelastic cotunneling through a strongly Coulomb-blockaded
quantum dot attached to two ferromagnetic leads in the weak coupling limit using a generic quantum Langevin equation approach. We first develop a Bloch-type equation microscopically to describe the
cotunneling-induced spin relaxation dynamics, and then develop explicit
analytical expressions for the local magnetization, current, and its
fluctuations. On this basis, we predict a novel zero-bias anomaly of
the differential conductance in the absence of a magnetic field for the
anti-parallel configuration, and asymmetric peak splitting in a magnetic field. Also, for the same system with large polarization, we find a negative
zero-frequency differential shot noise in the low positive bias-voltage
region. All these effects are ascribed to rapid spin-reversal due to
underlying spin-flip cotunneling. |
| |
Keywords: | quantum dot spin polarized tunneling cotunneling |
|
| 点击此处可从《理论物理通讯》浏览原始摘要信息 |
| 点击此处可从《理论物理通讯》下载免费的PDF全文 |
|