Probing electron dwell time in quantum dots through pulsed conductance analysis

The charge detection in the quantum dot is non-reproducible when measurements are repeated for the closed quantum dot. To investigate the origin of the non-reproducibility, the correlation between the electron dwell time and the non-reproducibility is studied. The electron dwell time is measured using real-time conductance measurement. The changes in conductance caused by electron tunneling in and out of the quantum dot are monitored using the charge detector. Statistical analysis was done to extract the electron dwell time in the quantum dot. Furthermore, the correlation between the electron dwell time and the tunnel barrier of the quantum dot is measured using pulse measurement technique. It was found that the electron dwell time decreases as the tunneling barrier of the quantum dot becomes thinner. Finally, in closed quantum dots, it was found that the origin of the non-reproducible charge detection is due to the longer dwell time than the time constant of the conductance measurement.