  Quantum metrology takes advantage of quantum correlations to enhance the
sensitivity of sensors and measurement techniques beyond their fundamental
classical limit given by the shot noise limit. The use of both temporal and
spatial correlations present in quantum states of light can extend
quantum-enhanced sensing to a parallel configuration that can simultaneously
probe an array of sensors or independently measure multiple parameters. To this
end, we use multi-spatial mode twin beams of light, which are characterized by
independent quantum-correlated spatial subregions in addition to quantum
temporal correlations, to probe a four-sensor quadrant plasmonic array. We show
that it is possible to independently and simultaneously measure local changes
in refractive index for all four sensors with a quantum enhancement in
sensitivity in the range of $22\%$ to $24\%$ over the corresponding classical
configuration. These results provide a first step towards highly parallel
spatially resolved quantum-enhanced sensing techniques and pave the way toward
more complex quantum sensing and quantum imaging platforms.
