Rydberg blockade entangling gates in silicon*

Spin qubits of donors in silicon show some of the longest coherence times recorded and promise seemless integration of quantum computing into current semiconductor fabrication. However, current entangling gate implementations rely on knowledge of the exact value of the exchange interaction between donors, which decays as a highly oscillating exponential, making high fidelity entangling gates in multi-qubit fabricated devices a challenge. In this work, we show how this constraint can be released by using Rydberg blockade entangling gates between orbital excited states of donors, which are robust against variations in the interaction strength. We obtain these results by calculating induced dipole interactions of shallow and singly ionised deep donors using the finite element method and by simulating the entangling gate pulse sequence in the presence of decoherence with a Markovian Lindblad Master equation. Our study paves the way for near-term large scale quantum computations with donors in silicon by lowering the precision requirements on single donor placement.