Optical Aharonov-Bohm effect in stacked type-II quantum dots

Kuskovsky, Igor L.; MacDonald, William M.; Govorov, Alexander O.; Mourokh, Lev G.; Wei, Xing; Tamargo, M. C.; Tadić, M.; Peeters, F. M.

doi:10.1103/physrevb.76.035342

Cited by 68 publications

(75 citation statements)

References 29 publications

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“…where L is the angular momentum quantum number, g E is the confined hole to electron ground state According to Eq.1, the rotating dipole shows a set of transitions between ground states with different This value is in agreement with morphological studies of ZnTe/ZnSe QDs [15]. We note that the electronic radius should be somewhat larger than the structural radius of the QD because the lateral localization of the electron is mostly due to the relatively-weak Coulomb potential [15].…”

supporting

confidence: 69%

“…The stacked columnar geometry of the system is of particular importance for the motion of the electron; it dictates the ring-like geometry of the electron motion. As was demonstrated theoretically in Ref [15], the electron inside an exciton in a single QD is localized either above or below a type-II QD and no AB effect is expected. In the stacked QDs, however, the motion is different because of the constraints due to the columnar nature of the stack: here the electron is forced to move in a plane laterally around a stack and, in this way, the AB effect can appear.…”

mentioning

confidence: 77%

“…The increased PL lifetime of the type-II QDs is directly related to the spatial separation of the charged particles and therefore reduction of the oscillator strength of the excitons. Furthermore, recent evidence also suggests that the QDs, which evolve from the clustering of Te-atoms in the ZnTe/ZnSe multilayer structure described here, also align vertically and therefore form columnar QD-like nanostructures [15]. This configuration is shown schematically in the inset to Figure 3(b).…”

mentioning

confidence: 93%

“…Although AB oscillations have been demonstrated in the emission energy in charged In(Ga)As QRs [13] and type-II InP/GaAs QDs [14], analogous effects were not observed in the PL intensity. In a very recent publication, a single AB i ntensity oscillation was demonstrated [15] for samples similar to those studied in this work, but oscillations in the luminescence energy were not reported.…”

mentioning

confidence: 99%

“…In the stacked QDs, however, the motion is different because of the constraints due to the columnar nature of the stack: here the electron is forced to move in a plane laterally around a stack and, in this way, the AB effect can appear. In addition, numerical calculations [15] show that the tunnel coupling between QDs in a stack is very weak and an exciton cannot move in the z-direction. Therefore, we assume that an exciton is localized in one of the stacked QDs.…”

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confidence: 99%

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Aharonov-Bohm Excitons at Elevated Temperatures in Type-IIZnTe/ZnSeQuantum Dots

et al. 2008

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Optical emission from type-II ZnTe/ZnSe quantum dots demonstrates large and persistent oscillations in both the peak energy and intensity indicating the formation of coherently rotating states. Furthermore, the Aharanov-Bohm (AB) effect is shown to be remarkably robust and persists until 180K. This is at least one order of magnitude greater than the typical temperatures in lithographically defined rings. To our knowledge this is the highest temperature at which the AB effect has been observed in semiconductor structures.

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supporting

confidence: 69%

mentioning

confidence: 77%

mentioning

confidence: 93%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Aharonov-Bohm Excitons at Elevated Temperatures in Type-IIZnTe/ZnSeQuantum Dots

et al. 2008

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Excitonic wavefunction engineering based on type II quantum dots

Dacal¹,

Iikawa

Brasil

2013

Physica Status Solidi (b)

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We propose a semiconductor heterostructure that allows an effective control of the shape of the carriers wavefunctions by varying just one main structural parameter. The structure is formed by a type II quantum dot and a type I quantum well. We present the results of calculations for a particular system consisting of an InP/GaAs quantum dot and an InGaAs/GaAs quantum well using a simple effective mass model that provides a good insight on our structure. We show that the wavefunction of the carrier that remains outside the dot changes from a spheroidal to a ring‐like shape depending mainly on the separation between the well and the dot layers. This change has a significant impact on relevant excitonic properties such as its lifetime and electrical dipole, and it also determines the possibility of observing the optical Aharonov–Bohm effect.

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Magneto‐optical specifications of Rosen‐Morse quantum dot with screw dislocation

Bahar

Ungan

2020

Int J of Quantum Chemistry

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This is the first study to consider a quantum dot with screw dislocation that has Rosen-Morse (RM) confinement potential, generated by a GaAs/GaAlAs heterostructure.An external magnetic field and Aharonov-Bohm (AB) flux field were also applied on RM quantum dot (RMQD) in order to stave the effects of a screw dislocation defect. The combined effect of the screw dislocation defect, the external magnetic field, and AB flux field on the total refractive index changes (TRICs) and the total absorption coefficients (TACs) of RMQD are thus investigated. Cylindrical coordinates are used due to the direction of application of the torsion and the external fields, as well as due to the structure's symmetry. The effective mass approximation and tridiagonal matrix methods are used in order to obtain the subband energy spectra and electronic wave functions of RMQD.The nonlinear optical specifications of RMQD are checked using compact-density-matrix formalism within the framework of the iterative method. Reviews without screw dislocation are also carried out in order to be able to clarify the effects of a screw dislocation defect on the optical properties, and then, both cases are deliberated. This study is the first attempt to analyze the AB flux field for RMQD without screw dislocation. In the present study, the influences of a screw dislocation defect on RMQD's TRICs and TACs are probed by considering different values of the external magnetic field and AB flux field, and the ranges of corresponding parameters on the optimum of the structure are specified. Moreover, the study also elucidates how to rule out the effects of screw dislocation on optical specifications by means of the external fields. Despite a certain screw dislocation, the frequency range is determined where the structure behaves as if it is perfect (namely, without screw dislocation) for its optimum, which in turn is crucial for experimental applications. K E Y W O R D SAharonov-Bohm flux field, magnetic field, nonlinear optical properties, quantum dot, screw dislocation, Rosen-Morse (RM) confinement potential

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Optical Aharonov-Bohm effect in stacked type-II quantum dots

Cited by 68 publications

References 29 publications

Aharonov-Bohm Excitons at Elevated Temperatures in Type-IIZnTe/ZnSeQuantum Dots

Aharonov-Bohm Excitons at Elevated Temperatures in Type-IIZnTe/ZnSeQuantum Dots

Excitonic wavefunction engineering based on type II quantum dots

Magneto‐optical specifications of Rosen‐Morse quantum dot with screw dislocation

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