Cotunneling current and shot noise in quantum dots |
| |
Authors: | Thielmann Axel Hettler Matthias H König Jürgen Schön Gerd |
| |
Institution: | Forschungszentrum Karlsruhe, Institut für Nanotechnologie, 76021 Karlsruhe, Germany. |
| |
Abstract: | We derive general expressions for the current and the shot noise, taking into account non-Markovian memory effects. In generalization of previous approaches, our theory is valid for an arbitrary Coulomb interaction and coupling strength and is applicable to quantum dots and more complex systems such as molecules. A fully consistent diagrammatic expansion up to second order in the coupling strength, taking into account cotunneling processes, allows for a study of transport in an intermediate coupling strength regime relevant to many current experiments. We discuss a single-level quantum dot as a first example, focusing on the Coulomb-blockade regime where the cotunneling processes dominate. We find super-Poissonian shot noise due to inelastic spin-flip cotunneling processes at an energy scale different from the one expected from first-order calculations. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|