Once called a “classically non-describable two-valuedness” by Pauli, the electron spin forms a qubit that is naturally robust to electric fluctuations. Paradoxically, a common control strategy is the integration of micromagnets to enhance the coupling between spins and electric fields, which in turn hampers its noise immunity and adds architectural complexity. Here we exploit a switchable interaction between spins and orbital motion of electrons in silicon quantum dots, without a micromagnet. The weak effects of the relativistic spin-orbit interaction in silicon are enhanced, leading to a speed-up in Rabi frequency by a factor of up to 650 by controlling the energy quantisation of electrons in the nanostructure. Fast electrical control is demonstrated in multiple de-vices and electronic configurations. Using the electrical drive, we achieve a coherencetimeT2,Hahn≈50μs, fast single-qubit gates with Tπ/2= 3ns, and gate fidelities of 99.93%, probed by randomised benchmarking. High-performance all-electrical control improves the prospects for scalable silicon quantum computing.

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