Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Estimation of Gaussian random displacement using non-Gaussian states   In continuous-variable quantum information processing, quantum error
correction of Gaussian errors requires simultaneous estimation of both
quadrature components of displacements on phase space. However, quadrature
operators $x$ and $p$ are non-commutative conjugate observables, whose
simultaneous measurement is prohibited by the uncertainty principle.
Gottesman-Kitaev-Preskill (GKP) error correction deals with this problem using
complex non-Gaussian states called GKP states. On the other hand, simultaneous
estimation of displacement using experimentally feasible non-Gaussian states
has not been well studied. In this paper, we consider a multi-parameter
estimation problem of displacements assuming an isotropic Gaussian prior
distribution and allowing post-selection of measurement outcomes. We derive a
lower bound for the estimation error when only Gaussian operations are used,
and show that even simple non-Gaussian states such as single-photon states can
beat this bound. Based on Ghosh's bound, we also obtain a lower bound for the
estimation error when the maximum photon number of the input state is given.
Our results reveal the role of non-Gaussianity in the estimation of
displacements, and pave the way toward the error correction of Gaussian errors
using experimentally feasible non-Gaussian states.

27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph