Charge and spin state readout of a double quantum dot coupled to a resonator

Understand

State readout is a key requirement for a quantum computer.

• For semiconductor-based qubit devices it is usually accomplished using a separate mesoscopic electrometer.
• Here we demonstrate a simple detection scheme in which a radio-frequency resonant circuit coupled to a semiconductor double quantum dot is used to probe its charge and spin states.
• These results demonstrate a new non-invasive technique for measuring charge and spin states in quantum dot systems without requiring a separate mesoscopic detector.