Relation between Wigner quasi-probabability distribution and statistical second-moment

3

Is there any relation between the Wigner quasi-probability distribution function $W$ and the statistical second-moment (also known as covariance matrix) of a density matrix of a continuous variable state, such as Gaussian state?

Kianoosh.kargar

Posted 2020-07-15T18:47:33.153

Reputation: 55

Answers

3

You mean something like $$W_{G}(\mathbf{r}) =\frac{2^{n}}{\pi^{n} \sqrt{\operatorname{Det} \sigma}} \mathrm{e}^{-(\mathbf{r}-\overline{\mathbf{r}})^{\top} \boldsymbol{\sigma}^{-1}(\mathbf{r}-\overline{\mathbf{r}})},$$ where $W_{G}(\mathbf{r})$ is the Wigner function corresponding to a Gaussian state, $\mathbf{\sigma}$ its covariance matrix, and $\overline{r}$ the vector of first moments?

If yes, then, see, for example, Eqn. (4.50) of Quantum Continuous Variables.

keisuke.akira

Posted 2020-07-15T18:47:33.153

Reputation: 1 383

Thank you very much. It's exactly what I wanted. – Kianoosh.kargar – 2020-07-16T14:21:50.010

1

Great, can you please accept this answer then?

– keisuke.akira – 2020-07-16T15:20:46.167