Supplied device models lose accuracy as Ciena’s analog designs shrink, because quantum effects that classical simulators can’t capture start to dominate. Ciena’s answer was to build its own models in Victory Atomistic, which couples the Poisson and Schrödinger equations in one self-consistent solve. Silvaco’s team worked with Ciena to refine the tool. Process data was sparse. Even so, on 5nm devices at room temperature the simulated trends line up with lab measurements. Cryogenic behavior for qubit work is harder: measuring it costs a great deal, so Ciena wants simulation to take over. Convergence at very low temperature and low bias is where the work continues.