Theoretical Statistics and Mathematics Unit, ISI Delhi

April 15, 2015 (Wednesday) ,
3:30 PM at Webinar

Speaker:
Ritabrata Sengupta,
Indian Statistical Institute, Delhi

Title:
From particle counting to tomography of Gaussian states and channels

Abstract of Talk

A quantum system assumed to be an unknown Gaussian state
$\rho$ in the complex Hilbert space $L^2(\mathbb{R}^n)$, is
determined my its momentum and position mean $(\mathbf{l},
\mathbf{m})$ and its covariance matrix $S$. To estimate the
state, i.e. to estimate the parameters mentioned above, we
shall use only counting measurements. This approach differs
from the standard approach of using continuous variable
measurement for Gaussian state estimation, available in
literature. We also determine the optimal number of such
measurements required for a $n$-mode unknown state.
As a corollary, we show that, this method can be used for
estimating an unknown Gaussian channel as well. This is an
upcoming joint work with Prof K R Parthasarathy.