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arXiv · 1509.02867

Effects of electron-phonon interactions on the electron tunneling spectrum of PbS quantum dots

H. Wang·E. Lhuillier·Q. Yu·A. Mottaghizadeh·C. Ulysse·A. Zimmers·A. Descamps-Mandine·B. Dubertret·H. Aubin
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Abstract

We present a tunnel spectroscopy study of single PbS Quantum Dots (QDs) as function of temperature and gate voltage. Three distinct signatures of strong electron-phonon coupling are observed in the Electron Tunneling Spectrum (ETS) of these QDs. In the shell-filling regime, the $8\times$ degeneracy of the electronic levels is lifted by the Coulomb interactions and allows the observation of phonon sub-bands that result from the emission of optical phonons. At low bias, a gap is observed in the ETS that cannot be closed with the gate voltage, which is a distinguishing feature of the Franck-Condon (FC) blockade. From the data, a Huang-Rhys factor in the range $S\sim 1.7 - 2.5$ is obtained. Finally, in the shell tunneling regime, the optical phonons appear in the inelastic ETS $d^2I/dV^2$.

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H. Wang, E. Lhuillier, Q. Yu, A. Mottaghizadeh, C. Ulysse, A. Zimmers, A. Descamps-Mandine, B. Dubertret, H. Aubin. 2015-09-09. Effects of electron-phonon interactions on the electron tunneling spectrum of PbS quantum dots. https://doi.org/10.1103/physrevb.92.041403

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