The diabatic SWAP gate based on Si-MOS quantum dots

The SWAP gate, as a basic two-qubit gate, is essential for the realization and scale of the quantum process. The coherence exchange oscillation, under the condition of J>>ΔE_z, is an excellent phenomenon capable of demonstrating the two quantum gates. Our experiments present a coherence SWAP gate in an isotopically enriched silicon quantum dot system. By diabatic modifying the detuning, we observe the ratio of J/ΔE_z changes more than two orders of magnetics, thus guaranteeing the independent Elzerman readout while realizing the exchange oscillation. Combined with the independent single shot readout, we estimate the upper bound of the SWAP gate fidelity, which is improved by the magnetic field gradient between the two quantum dots. Our experiment provides a scheme to demonstrate the high fidelity coherence SWAP gate for the devices with the low longitude magnetic field gradient between qubits.