  We propose a continuous-variable quantum sensing scheme, in which a harmonic
oscillator is employed as the probe to estimate the parameters in the spectral
density of a quantum reservoir, within a non-Markovian dynamical framework. It
is revealed that the sensing sensitivity can be effectively boosted by (i)
optimizing the weight of the momentum-position-type coupling in the whole
probe-reservoir interaction Hamiltonian, (ii) the initial quantum squeezing
resource provided by the probe, (iii) the noncanonical equilibration induced by
the non-Markovian effect, and (iv) applying an external driving field. Our
results may have some potential applications in understanding and controlling
the decoherence of dissipative continuous-variable systems.
