Electronic phase coherence versus dissipation in solid-state quantum devices: Two approximations are better than one
| Autor: | Iotti, Rita Claudia, Rossi, Fausto |
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| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | EPL, 112 (2015) 67005 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1209/0295-5075/112/67005 |
| Popis: | In the microscopic modeling of new-generation electronic quantum nanodevices a variety of simulation strategies have been proposed and employed. Aim of this Letter is to point out virtues versus intrinsic limitations of non-Markovian density-matrix approaches; we shall show that the usual mean-field treatment may lead to highly unphysical results, like negative distribution probabilities and non-dissipative behaviours, which are particularly severe in zero-dimensional electronic systems coupled to dispersionless phonon modes. This is in striking contrast with Markovian treatments, where a proper combination of adiabatic limit and mean-field schemes guarantees a physically acceptable solution; as a result, the unusual conclusion is that two approximations are better than one. Comment: 6 pages, 6 figures |
| Databáze: | arXiv |
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