Fast Volume Integral Equation Based Modeling of Quantum Gate Circuitry: Capturing Local vs. Nonlocal Effects on Spin Qubits

We develop a fast volume integral equation solver in frequency domain to model and simulate nonlocal optical responses in quantum nano-electromagnetic gate circuitry. The convolution involved in the nonlocal constitutive relation is handled efficiently by transforming it to the spectral Fourier domain using fast Fourier transform (FFT), in conjunction with the convolution of Green's function with equivalent volumetric currents. Numerical simulations of 3-D quantum gate devices demonstrate the capability of the proposed solver as well as the importance of nonlocal effects.