  The sensitivities of ground-based gravitational-wave (GW) detectors are
limited by quantum shot noise at a few hundred Hertz and above. Nonetheless,
one can use a quantum-correlation technique proposed by Martynov, et al. [Phys.
Rev. A 95, 043831 (2017)] to remove the expectation value of the shot noise,
thereby exposing underlying classical signals in the cross spectrum formed by
cross-correlating the two outputs in a GW interferometer's anti-symmetric port.
We explore here the prospects and analyze the sensitivity of using quantum
correlation to detect astrophysical GW signals. Conceptually, this technique is
similar to the correlation of two different GW detectors as it utilizes the
fact that a GW signal will be correlated in the two outputs but the shot noise
will be uncorrelated. Quantum correlation also has its unique advantages as it
requires only a single interferometer to make a detection. Therefore, quantum
correlation could increase the duty cycle, enhance the search efficiency, and
enable the detection of highly polarized signals. In particular, we show that
quantum correlation could be especially useful for detecting post-merger
remnants of binary neutron stars with both short ($< 1\,{\rm s}$) and
intermediate ($\sim 10-10^4\,{\rm s}$) durations and setting upper limits on
continuous emissions from unknown pulsars.
