Algebraic order and the BKT transition in an exciton-polariton gas
Abstract/Contents
- Abstract
- Below a critical temperature, three-dimensional bosonic gases form a Bose-Einstein-condensate which exhibits spatial coherence. In two-dimensional (2D) systems, true long range order is impossible at non-zero temperatures since long-range fluctuations which increase the entropy and destroy the coherence can easily be excited. However it has been predicted by the Berezinskii-Kosterlitz-Thouless (BKT) theory that such a 2D condensate can exhibit quasi-long-range order which is characterized by a power-law decay of the spatial correlation function. This thesis presents the first observation of the coherence decay in a 2D exciton-polariton condensate with a power-law whose exponent (less than 1/4) behaves as predicted by the theory. Exciton-polaritons are quasi-particles which can be described as the quantum mechanical superposition of an exciton in a quantum well and a photon trapped in a semiconductor cavity. Due to their bosonic properties and small effective mass, they already condense at a temperature of a few kelvin, compared to a few hundred nanokelvin in the atomic case. Exciton-polaritons are created by optical excitation of the sample, and they continuously decay through the leakage of photons out of the sample. These leaking photons preserve the coherence properties of the decaying exciton-polaritons, and their coherence can be determined through interference measurements.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2014 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Nitsche, Wolfgang Hartmut | |
|---|---|---|
| Associated with | Stanford University, Department of Applied Physics. | |
| Primary advisor | Yamamoto, Yoshihisa | |
| Thesis advisor | Yamamoto, Yoshihisa | |
| Thesis advisor | Mabuchi, Hideo | |
| Thesis advisor | Miller, D. A. B | |
| Advisor | Mabuchi, Hideo | |
| Advisor | Miller, D. A. B |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Wolfgang Hartmut Nitsche. |
|---|---|
| Note | Submitted to the Department of Applied Physics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2014. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2014 by Wolfgang Hartmut Nitsche
Also listed in
Loading usage metrics...