Terahertz Intersublevel Transitions in Single Self-Assembled InAs Quantum Dots with Variable Electron Numbers
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2015-01-12 |
| Journal | Nano Letters |
| Authors | Ya Zhang, Kenji Shibata, N. Naomi, Camille Ndebeka-Bandou, G. Bastard |
| Institutions | The University of Tokyo, Ăcole Normale SupĂ©rieure - PSL |
| Citations | 19 |
Abstract
Section titled âAbstractâWe propose a method for performing terahertz spectroscopy on nanometer (nm)-scale systems by using metal nanogap electrodes. Intersublevel transition spectra of single self-assembled InAs quantum dots (QDs) have been measured with high signal/noise ratios by using a single electron transistor geometry that consists of a QD and nanogap metal electrodes as a terahertz detector. Photocurrent distribution with respect to the Coulomb diamonds indicates that there are two mechanisms for the photocurrent generation. When the p shell was fully occupied, we observed rather simple photocurrent spectra induced by the p â d transitions. However, when the p shell was half-filled, the photocurrent spectra exhibited a markedly different behavior, which we attribute to the fluctuation in electron configuration when the empty p state is filled back from the electrodes.