Radiofrequency cascade readout of coupled spin qubits

Understand

Silicon spin qubits based on metal-oxide-semiconductor (MOS) technology are compatible with semiconductor manufacturing and offer a route to scalable quantum processing.

• However, spin readout typically relies on proximal charge sensors, which add architectural complexity and limit qubit connectivity.
• In situ dispersive readout techniques are more compact, which can alleviate these constraints, but exhibit limited sensitivity.
• Here we report a radiofrequency electron-cascade readout method that enhances the dispersive signal through alternating-current electron co-tunnelling.