Questions tagged [gaussian-states]
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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 ...
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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 = \...
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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♦
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