Fig. 3: Analysis of spin-mechanical coupling profiles and the defect cell parameters that affect this coupling.

(a) and (b) shows the 2D and 1D spin-mechanical coupling g_sm profile of the spin-optomechanical crystal breathing mode, with expected position of the Group IV spin overlayed. The parameters b, a_d, \({h}_{{x}_{d}}\), and \({h}_{{y}_{d}}\) impact the spin-mechanical coupling strength among other variables. The one-dimensional profile in the center of the bridge shows that strain is maximized at the bridge edge but retained in the center away from sidewalls. The crystal axis orientation in the device affects g_sm (c) and g_om (d, red) by changing the strain elements the spin sees and the photoelastic effect for g_pe (d, yellow), which sums with a constant g_mb (d, gray). e Sweeping b, a_d, \({h}_{{x}_{d}}\), and \({h}_{{y}_{d}}\) about a naive parameter set shows that the parameters governing device performance, namely var ∈ {Q_opt, g_om, g_sm}, are maximized about different variables, motivating protocol-based numerical optimization of the exact design parameters. Q_mech was routinely near 10⁶ or greater in the sweeps and not depicted. These sweeps are centered around the following parameters \(\{{h}_{{y}_{d}},{h}_{{x}_{d}},{a}_{d}\}=\{220.5,341.25,456.75\}\) nm, α = 135°; the rest of the parameters are the same as in Table 1.