Questions tagged [gaussian-states]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
0 answers

Vmod in Gaussian Modulated QKD

In the paper "Continuous-Variable Quantum Key Distribution with Gaussian Modulation – The Theory of Practical Implementations" by Fabian Laudenbach, there's a distinction between the ...
Troncho Col's user avatar
2 votes
1 answer

How to write the covariance matrix of a quantum gaussian state as a function of photon numbers?

Assume having a one-mode quantum Gaussian state with quadrature observable vector $\hat r = [\hat q , \hat p ] $ and covariance matrix $\sigma$. According to definition [1]: \begin{equation} \sigma = \...
hafezmg48's user avatar
6 votes
1 answer

Why is a state Gaussian if and only if its covariance matrix satisfies $\boldsymbol\sigma+i\boldsymbol\Omega\ge0$?

Let $\rho$ be a Gaussian state, described by the $2N\times 2N$ covariance matrix $\newcommand{\bs}[1]{{\boldsymbol{#1}}}\bs\sigma$. Denote with $\bs\Omega$ the $N$-mode symplectic form associated with ...
glS's user avatar
  • 23.4k