Efficient Simulation of Correlated Dynamics in Quantum-Dot Cellular Automata (QCA)

Many simulations of quantum-dot cellular automata (QCA) rely upon the so-called intercellular Hartree approximation (ICHA), which neglects the possibility of entanglement between cells. While the ICHA is useful for solving many QCA circuits due to its relative simplicity and computational efficiency, its many shortcomings make it prohibitive in accurately modeling the dynamics of large systems of QCA cells. On the other hand, solving a full Hamiltonian for each circuit, while more accurate, becomes computationally intractable as the number of cells increases. This paper aims to find an intermediate solution that exists somewhere in the solution space spanned by the ICHA and the full Hamiltonian. The development of such a solution promises to yield significant results within the QCA research community.