On the dark nature of exciton Bose-Einstein condensate
| dc.creator | Combescot, Monique | |
| dc.creator | Leuenberger, Michael N. | |
| dc.date | 2008-07-29 | |
| dc.date.accessioned | 2026-07-07T09:53:34Z | |
| dc.date.available | 2026-07-07T09:53:34Z | |
| dc.description | We show that for the very same reason that excitons are bright, i.e. coupled to photons, they have a higher energy than dark excitons, even for electrons spatially separated from holes, such as in a double quantum well. Indeed, the same channel which produces the finite electron-hole effective overlap responsible for the absorption and emission of photon allows for Coulomb interband exchange processes, which are nothing but a sequence of virtual recombination and creation of one electron-hole pair. Consequently, this additional repulsive electron-hole Coulomb exchange interaction exists for bright excitons, but not for dark excitons. If we now remember that dark excitons with spins $\pm 2$ are formed in a natural way through carrier exchange between two opposite spin bright excitons, we are led to predict that in a double quantum well sample with one trap -- a configuration appropriate to get high density -- exciton Bose-Einstein condensation should appear when cooling down the sample as a dark spot made of $(\pm 2)$ excitons at the center of the trap. | |
| dc.description | 6 pages, 6 figures | |
| dc.identifier | https://arxiv.org/abs/0807.4724 | |
| dc.identifier | http://arxiv.org/abs/0807.4724 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/165999 | |
| dc.subject | Strongly Correlated Electrons | |
| dc.title | On the dark nature of exciton Bose-Einstein condensate | |
| dc.type | text |