A second-order coherence function of an exciton-polariton condensate is calculated in the time domain by the quantum Monte-Carlo wavefunction method.We fully consider polariton-polariton interactions within the five lowest quantized exciton-polariton branch in a one-dimensional model.Our calculated second-order coherence function qualitatively agrees with the experimental results obtained by H. Deng et.al, 1) and it approaches to one at well above threshold like an ideal photon laser.However, the polariton number distribution is broad compared with Poissonian distribution, which indicates that the polariton condensate is different from a coherent state.A second-order coherence function of an exciton-polariton condensate is calculated in the time domain by the quantum Monte-Carlo wavefunction method.We fully consider polariton-polariton interactions within the five lowest quantized exciton-polariton branch in a one-dimensional model.Our calculated second-order coherence function qualitatively agrees with the experimental results obtained by H. Deng et.al, 1) and it approaches to one at well above threshold like an ideal photon laser.However, the polariton number distribution is broad compared with Poissonian distribution, which indicates that the polariton condensate is different from a coherent state.

Jan 1, 20140 citations

Higher order coherence of exciton-polariton condensates

Tomoyuki Horikiri, P. Schwendimann, A. Quattropani +3 more

The second- and third-order coherence functions ${g}^{(n)}(0)$ ( $n=2$ and 3) of an exciton-polariton condensate are measured and compared to the theory. Contrary to an ideal photon laser, deviation from unity in the second- and third-order coherence functions is observed, thus showing a bunching effect, but not the characteristics of a standard thermal state with ${g}^{(n)}(0)=n!$ . The increase in bunching with the order of the coherence function, ${g}^{(3)}(0)>{g}^{(2)}(0)>1$ , indicates that the polariton condensate is different from a coherent state, a number state, or a thermal state. The measurement of third-order coherence has the advantage, compared to the second-order one, that the difference between a thermal state and a coherent state is more pronounced. The experimental results are in agreement with the theoretical model where polariton-polariton and polariton-phonon interactions are responsible for the loss of temporal coherence.The second- and third-order coherence functions ${g}^{(n)}(0)$ ($n=2$ and 3) of an exciton-polariton condensate are measured and compared to the theory. Contrary to an ideal photon laser, deviation from unity in the second- and third-order coherence functions is observed, thus showing a bunching effect, but not the characteristics of a standard thermal state with ${g}^{(n)}(0)=n!$. The increase in bunching with the order of the coherence function, ${g}^{(3)}(0)>{g}^{(2)}(0)>1$, indicates that the polariton condensate is different from a coherent state, a number state, or a thermal state. The measurement of third-order coherence has the advantage, compared to the second-order one, that the difference between a thermal state and a coherent state is more pronounced. The experimental results are in agreement with the theoretical model where polariton-polariton and polariton-phonon interactions are responsible for the loss of temporal coherence.

arXiv:0910.2978Physical Review BJan 25, 201067 citations

The second- and third-order coherence functions

{g}^{(n)}(0)

(

n=2

and 3) of an exciton-polariton condensate are measured and compared to the theory. Contrary to an ideal photon laser, deviation from unity in the second- and third-order coherence functions is observed, thus showing a bunching effect, but not the characteristics of a standard thermal state with

{g}^{(n)}(0)=n!

. The increase in bunching with the order of the coherence function,

{g}^{(3)}(0)>{g}^{(2)}(0)>1

, indicates that the polariton condensate is different from a coherent state, a number state, or a thermal state. The measurement of third-order coherence has the advantage, compared to the second-order one, that the difference between a thermal state and a coherent state is more pronounced. The experimental results are in agreement with the theoretical model where polariton-polariton and polariton-phonon interactions are responsible for the loss of temporal coherence.