Abstract
The lifetime of dense orthoexcitons in Cu2O is severely limited by dark molecule formation. In order to investigate this two-body process for orthoexciton-polaritons, we employ two-photon excitation and resonantly create orthoexciton-polaritons at 2 K, which are the coherent quantum superposition of orthoexcitons and the light field. Based on the steady-state analysis, we find that this density-dependent process is an order of magnitude reduced for resonantly created orthoexciton-polaritons compared with thermalized orthoexcitons at 2 K. This most likely arises from the photonic character of an orthoexciton-polariton. Considering the greatly reduced effective mass of the orthoexciton-polariton, this implies that the experimentally achievable orthoexciton-polariton densities can be above the critical density for Bose-Einstein condensation. However, insufficient elastic scattering seems to keep this propagating quantum ensemble from internal equilibrium.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 128-132 |
| Number of pages | 5 |
| Journal | Solid State Communications |
| Volume | 146 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - Apr 2008 |
Funding
The authors would like to thank J. P. Wolfe at the University of Illinois for providing the sample used in this work. This work is supported by the National Science Foundation under a US/Ireland corperation, Grant 0306731, and the Northwestern Materials Research Center under NSF Grant DMR-0520513.
Keywords
- D. Orthoexciton-polariton
- D. Two-body process
- E. Two-photon excitation
ASJC Scopus subject areas
- General Chemistry
- Condensed Matter Physics
- Materials Chemistry