Photocreation of a dark electron-hole pair in a quantum dot

Autor: Shiau, Shiue-Yuan, Eble, Benoit, Voliotis, Valia, Combescot, Monique
Rok vydání: 2020
Předmět:
Zdroj: Phys. Rev. B 101, 161405(R) (2020)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.101.161405
Popis: Photon absorption in a semiconductor produces bright excitons that recombine very fast into photons. We here show that in a quantum dot set close to a p-doped reservoir, this absorption can produce a dark duo, i.e., an electron-hole pair that does not emit light. This unexpected effect relies on the fact that the wave function for a hole leaks out of a finite-barrier dot less than for electron. This difference can render the positively charged trio unstable in the dot by tuning the applied bias voltage in a field-effect device. The unstable trio that would result from photon absorption in a positively charged dot, has to eject one of its two holes. The remaining duo can be made dark with a probability close to 100% after a few pumping cycles with linearly polarized photons, in this way engineering long-lived initial states for quantum information processing.
Comment: 5 pages, 3 figures, to be published in Phys. Rev. B Rapid Comm
Databáze: arXiv