Decoherence due to contacts in ballistic nanostructures
| dc.creator | Knezevic, I. | |
| dc.date | 2008-01-25 | |
| dc.date | 2008-06-25 | |
| dc.date.accessioned | 2026-07-07T09:46:17Z | |
| dc.date.available | 2026-07-07T09:46:17Z | |
| dc.description | The active region of a ballistic nanostructure is an open quantum-mechanical system, whose nonunitary evolution (decoherence) towards a nonequilibrium steady state is determined by carrier injection from the contacts. The purpose of this paper is to provide a simple theoretical description of the contact-induced decoherence in ballistic nanostructures, which is established within the framework of the open systems theory. The active region's evolution in the presence of contacts is generally non-Markovian. However, if the contacts' energy relaxation due to electron-electron scattering is sufficiently fast, then the contacts can be considered memoryless on timescales coarsened over their energy relaxation time, and the evolution of the current-limiting active region can be considered Markovian. Therefore, we first derive a general Markovian map in the presence of a memoryless environment, by coarse-graining the exact short-time non-Markovian dynamics of an abstract open system over the environment memory-loss time, and we give the requirements for the validity of this map. We then introduce a model contact-active region interaction that describes carrier injection from the contacts for a generic two-terminal ballistic nanostructure. Starting from this model interaction and using the Markovian dynamics derived by coarse-graining over the effective memory-loss time of the contacts, we derive the formulas for the nonequilibrium steady-state distribution functions of the forward and backward propagating states in the nanostructure's active region. On the example of a double-barrier tunneling structure, the present approach yields an I-V curve with all the prominent resonant features. The relationship to the Landauer-Büttiker formalism is also discussed, as well as the inclusion of scattering. | |
| dc.description | Published version | |
| dc.identifier | https://arxiv.org/abs/0801.4012 | |
| dc.identifier | http://arxiv.org/abs/0801.4012 | |
| dc.identifier | Phys. Rev. B 77, 125301 (2008) | |
| dc.identifier | doi:10.1103/PhysRevB.77.125301 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/163479 | |
| dc.subject | Mesoscale and Nanoscale Physics | |
| dc.title | Decoherence due to contacts in ballistic nanostructures | |
| dc.type | text |