We show how "single" quantum dots, each hosting a singlet-triplet qubit, can be placed in arrays to build a spin quantum cellular automaton. A fast (∼ 10 ns) deterministic coherent singlet-triplet filtering, as opposed to current incoherent tunneling/slow-adiabatic based quantum gates (operation time ∼ 300 ns), can be employed to produce a two-qubit gate through capacitive (electrostatic) coupling that can operate over significant distances. This is the coherent version of the widely discussed

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... harge and nano-magnet cellular automata and would offer speed, reduce dissipation, perform quantum computation, while interfacing smoothly with its classical counterpart. This combines the best of two worlds -- the coherence of spin pairs known from quantum technologies, and the strength and range of electrostatic couplings from the charge based classical cellular automata.