|
Document Type |
: |
Article In Journal |
|
Document Title |
: |
Photonic Crystal Architecture for Room-Temperature Equilibrium Bose-Einstein Condensation of Exciton Polaritons Photonic Crystal Architecture for Room-Temperature Equilibrium Bose-Einstein Condensation of Exciton Polaritons |
|
Subject |
: |
physics |
|
Document Language |
: |
English |
|
Abstract |
: |
We describe photonic crystal microcavities with very strong light-matter interaction to realize roomtemperature,
equilibrium, exciton-polariton Bose-Einstein condensation (BEC). This goal is achieved
through a careful balance between strong light trapping in a photonic band gap (PBG) and large exciton
density enabled by a multiple quantum-well (QW) structure with a moderate dielectric constant. This
approach enables the formation of a long-lived, dense 10 - mu m - 1 - cm- scale cloud of exciton
polaritons with vacuum Rabi splitting that is roughly 7% of the bare exciton-recombination energy. We
introduce a woodpile photonic crystal made of Cd-0.6 Mg-0.4 Te with a 3D PBG of 9.2% (gap-tocentral-
frequency ratio) that strongly focuses a planar guided optical field on CdTe QWs in the cavity.
For 3-nm QWs with 5-nm barrier width, the exciton-photon coupling can be as large as (h) over bar
Omega = 55 meV (i.e., a vacuum Rabi splitting of 2 (h) over bar Omega = 110 meV). The excitonrecombination
energy of 1.65 eV corresponds to an optical wavelength of 750 nm. For N = 106 QWs
embedded in the cavity, the collective exciton-photon coupling per QW ((h) over bar Omega/root N =
5.4 meV) is much larger than the state-of-the-art value of 3.3 meV, for the CdTe Fabry-Perot
microcavity. The maximum BEC temperature is limited by the depth of the dispersion minimum for the
lower polariton branch, over which the polariton has a small effective mass of approximately 10(-5)m(0),
where m(0) is the electron mass in vacuum. By detuning the bare exciton-recombination energy above
the planar guided optical mode, a larger dispersion depth is achieved, enabling room-temperature BEC.
The BEC transition temperature ranges as high as 500 K when the polariton density per QW is
increased to (11a(B))(-2), where a(B) similar or equal to 3.5 nm is the exciton Bohr radius and the
exciton-cavity detuning is increased to 30 meV. A high-quality PBG can suppress exciton radiative
decay and enhance the polariton lifetime to beyond 150 ps at room temperature, sufficient for thermal
equilibrium BEC. |
|
ISSN |
: |
2160-3308 |
|
Journal Name |
: |
PHYSICAL REVIEW X |
|
Volume |
: |
4 |
|
Issue Number |
: |
3 |
|
Publishing Year |
: |
1435 AH
2014 AD |
|
Article Type |
: |
Article |
|
Added Date |
: |
Monday, July 31, 2017 |
|
Researchers
| Jian-Hua Jiang | Jiang, Jian-Hua | Investigator | Doctorate | |
| Sajeev John | John, Sajeev | Researcher | Doctorate | |
|