Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum state tomography of an itinerant squeezed microwave field   We perform state tomography of an itinerant squeezed state of the microwave
field prepared by a Josephson parametric amplifier (JPA). We use a second JPA
as a pre-amplifier to improve the quantum efficiency of the field quadrature
measurement (QM) from 2% to 36 +/- 4%. Without correcting for the detection
inefficiency we observe a minimum quadrature variance which is 69 +/- 8% of the
variance of the vacuum. We reconstruct the state's density matrix by a maximum
likelihood method and infer that the squeezed state has a minimum variance less
than 40% of the vacuum, with uncertainty mostly caused by calibration
systematics.

16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph