| We demonstrate real-time detection of single electron interference in a double quantum dot embedded in an Aharonov-Bohm interferometer, with visibility approaching unity. We use a quantum point contact as a charge detector to perform time-resolved measurements of single-electron tunneling. With increased bias voltage across the quantum point contact a back-action is exerted on the interferometer leading to decoherence. We attribute this to emission of radiation from the quantum point contact, which drives non-coherent electronic transitions in the quantum dots. Surprisingly, the efficiency of this process depends strongly on magnetic field, with variations occurring on a field scale much smaller than the magnetic field associated with one flux quantum penetrating the quantum dot. |
|