Ab-initio tree-tensor-network digital twin for quantum computer benchmarking in 2D

Large-scale numerical simulations of the Hamiltonian dynamics of a noisy intermediate scale quantum computer-a digital twin-could play a major role in developing efficient and scalable strategies for tuning quantum algorithms for specific hardware. Via a two-dimensional tensor network digital twin of a Rydberg atom quantum computer, we demonstrate the feasibility of such a program. In particular, we quantify the effects of gate crosstalks induced by the van der Waals interaction between Rydberg atoms: according to an 8x8 digital twin simulation based on the current state-of-the-art experimental setups, the initial state of a five-qubit repetition code can be prepared with a high fidelity, a first indicator for a compatibility with fault-tolerant quantum computing. The preparation of a 64-qubit Greenberger-Horne-Zeilinger state with about 700 gates yields a 99.9% fidelity in a closed system while achieving a speedup of 35% via parallelization.