Enhanced life time and suppressed efficiency roll-off in phosphorescent organic light-emitting diodes with multiple quantum well structures AIP Advances 2, 012117 (2012) Effect of temperature and strain on the optical polarization of (In)(Al)GaN ultraviolet light emitting diodes Appl. Phys. Lett. 99, 261105 (2011) Optoelectronic behaviors and carrier dynamics of individual localized luminescent centers in InGaN quantum-well light emitting diodes Appl. Phys. Lett. 99, 251911 (2011) Room temperature ballistic transport in InSb quantum well nanodevices Appl. Phys. Lett. 99, 242101 (2011) Pt/CdTe/Pt asymmetric nano-Schottky diodes from colloidal quantum dots AIP Advances 1, 042166 (2011) Additional information on AIP Conf. Proc. , Hongo, Japan Abstract. We characterize and model the single-particle energy level position and resonant current strength at a threelevel crossing in a coherent mixer composed of two weakly coupled vertical quantum dots. In addition to clear anticrossing behavior, an otherwise strong resonance is completely extinguished at the center of the crossing. Despite the strong variation in energy level position and resonant current strength throughout the crossing region, the resonance widths and the sum of the branch currents are found to be approximately constant.

We outline power spectra and auto correlation analysis performed on temporal oscillations in the tunneling current of coupled vertical quantum dots. The current is monitored for ~2325 s blocks as the magnetic field is stepped through a high bias feature displaying hysteresis and switching: hallmarks of the hyperfine interaction. Quasi-periodic oscillations of ~2 pA amplitude and of ~100 s period are observed in the current inside the hysteretic feature. Compared to the baseline current outside the hysteretic feature the power spectral density is enhanced by up to three orders of magnitude and the auto correlation displays clear long lived oscillations about zero.

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