Suppression of the Aharonov-Bohm effect in hexagonal quantum rings

Ballester, Ana; Segarra, Carlos; Bertoni, Alberto; Planelles, Josep

doi:10.1209/0295-5075/104/67004

Cited by 8 publications

(6 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the flux periodicity is also disturbed by the shell thickness. Flux periodic energy spectra for thin polygonal shells, without spin effects, have already been obtained by other authors [16,45,46].…”

Section: Effects Of a Longitudinal Magnetic Fieldsupporting

confidence: 54%

Conductance features of core-shell nanowires determined by the internal geometry

Torres,

Sitek,

Erlingsson

et al. 2018

Preprint

View full text Add to dashboard Cite

We consider electrons in tubular nanowires with prismatic geometry and infinite length. Such a model corresponds to a core-shell nanowire with an insulating core and a conductive shell. In a prismatic shell the lowest energy states are localized along the edges (corners) of the prism and are separated by a considerable energy gap from the states localized on the prism facets. The corner localization is robust in the presence of a magnetic field longitudinal to the wire. If the magnetic field is transversal to the wire the lowest states can be shifted to the lateral regions of the shell, relatively to the direction of the field. These localization effects should be observable in transport experiments on semiconductor core-shell nanowires, typically with hexagonal geometry. We show that the conductance of the prismatic structures considerably differs from the one of circular nanowires. The effects are observed for sufficiently thin hexagonal wires and become much more pronounced for square and triangular shells. To the best of our knowledge the internal geometry of such nanowires is not revealed in experimental studies. We show that with properly designed nanowires these localization effects may become an important resource of interesting phenomenology.

show abstract

Section: Effects Of a Longitudinal Magnetic Fieldsupporting

confidence: 54%

Conductance features of core-shell nanowires determined by the internal geometry

Torres,

Sitek,

Erlingsson

et al. 2018

Preprint

View full text Add to dashboard Cite

show abstract

“…Strong anisotropy-induced effects are predicted in this case, such as negative magnetoresistance in a transverse magnetic field [24] and symmetry-induced cancellation of the AB effect in hexagonal quantum rings [25]. The inhomogeneous electron gas localization was crucially exposed in the recent observation of intra-and interband excitations [23,26].…”

Section: Introductionmentioning

confidence: 85%

“…Such approximations are particularly severe in radial heterostructures, where coupling between the discrete (hexagonal in InAs or GaAs) symmetry and many-electron interactions leads to strongly inhomogeneously distributed electron gas and, in turn, to the coexistence of 1D and 2D channels at the corners and facets of the hexagonal hetero-interfaces. [21][22][23] Strong anisotropy-induced effects are predicted in this case, such as negative magneto-resistance in a transverse magnetic field 24 and symmetry-induced cancellation of the AB effect in hexagonal quantum rings 25 The inhomogeneous electron gas localization was crucially exposed in the recent observation of intra-and inter-band excitations. 23,26 In this paper we study the electronic states and magnetoconductance in GaAs/InAs core-shell NWs with an axial magnetic field within a spin-density-functional theory (SDFT) approach.…”

Section: Introductionmentioning

confidence: 88%

Aharonov-Bohm oscillations and electron gas transitions in hexagonal core-shell nanowires with an axial magnetic field

et al. 2015

View full text Add to dashboard Cite

We use spin-density-functional theory within an envelope function approach to calculate electronic states in a GaAs/InAs core-shell nanowire pierced by an axial magnetic field. Our fully three-dimensional quantum modeling includes explicitly a description of the realistic cross section and composition of the sample, and the electrostatic field induced by external gates in two different device geometries: gate-all-around and back-gate. At low magnetic fields, we investigate Aharonov-Bohm oscillations and signatures therein of the discrete symmetry of the electronic system, and we critically analyze recent magnetoconductance observations. At high magnetic fields, we find that several charge and spin transitions occur. We discuss the origin of these transitions in terms of different localization and Coulomb regimes, and we predict their signatures in magnetoconductance experiments.

show abstract

“…shorter than their wavelength, can be considered as quantum rings. Such structures are of particular interest due to the possibility of controlling the number of carriers in the system and its fluctuations [1,2], and offer the possibility to study artificial atoms and their features as they exhibit shell structures similar to those of real atoms.…”

Section: Introductionmentioning

confidence: 99%

Controlled Coulomb effects in core-shell quantum rings

Sitek

Torres

Torfason

et al. 2017

2017 19th International Conference on Transparent Optical Networks (ICTON)

View full text Add to dashboard Cite

We analyse theoretically the possibilities of contactless control of in-gap states formed by a pair of electrons confined in a triangular quantum ring. The in-gap states are corner-localized states associated with two electrons occupying the same corner area, and thus shifted to much higher energies than other corner states, but still they are below the energies of corner-side-localized states. We show how the energies, degeneracy and splittings between consecutive levels change with the orientation of an external electric field relatively to the polygonal cross section. We also show how absorption changes in the presence of external electric and magnetic fields.

show abstract

Suppression of the Aharonov-Bohm effect in hexagonal quantum rings

Cited by 8 publications

References 33 publications

Conductance features of core-shell nanowires determined by the internal geometry

Conductance features of core-shell nanowires determined by the internal geometry

Aharonov-Bohm oscillations and electron gas transitions in hexagonal core-shell nanowires with an axial magnetic field

Controlled Coulomb effects in core-shell quantum rings

Contact Info

Product

Resources

About