RESUMO
The harmonic oscillator is a foundational concept in both theoretical and experimental quantum mechanics. Here, we demonstrate harmonic oscillators in a semiconductor platform by faithfully implementing continuously graded alloy semiconductor quantum wells. Unlike current technology, this technique avoids interfaces that can hamper the system and allows for the production of multiwell stacks several micrometers thick. The experimentally measured system oscillations are at 3 THz for two structures containing 18 and 54 parabolic quantum wells. Absorption at room temperature is achieved: this is as expected from a parabolic potential and is unlike square quantum wells that require cryogenic operation. Linewidths below 11% of the central frequency are obtained up to 150 K, with a 5.6% linewidth obtained at 10 K. Furthermore, we show that the system correctly displays an absence of nonlinearity despite electron-electron interactions-analogous to the Kohn theorem. These high-quality structures already open up several new experimental vistas.
RESUMO
The so called 'incomplete hole shell filling' phenomenon, that is the breaking of the Aufbau principle was reported by Reuter et al (Phys. Rev. Lett. 94 026808) in the hole charging spectra of a quantum dot when the results were interpreted in the context of the s/p/d shell system-typical for electrons. We report an example of an inter-particle-interaction induced Aufbau principle violation even if it is applied to the one-particle Kohn-Luttinger eigenstates. We present a [Formula: see text]/configuration-interaction study that concerns multiple holes confined in an InGaAs/GaAs self-assembled cylindrical quantum dot. The eigenenergies and eigenvectors of up to six hole ground states were obtained-along with the corresponding one-hole orbital occupations-and discussed in the context of the Aufbau principle.