Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: QND measurements for future gravitational-wave detectors   Second-generation interferometric gravitational-wave detectors will be
operating at the Standard Quantum Limit, a sensitivity limitation set by the
trade off between measurement accuracy and quantum back action, which is
governed by the Heisenberg Uncertainty Principle. We review several schemes
that allows the quantum noise of interferometers to surpass the Standard
Quantum Limit significantly over a broad frequency band. Such schemes may be an
important component of the design of third-generation detectors.

24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg