Electronic and optical properties of an electro-magnetic non-uniform narrow quantum ring under repulsive scattering centre

ABSTRACT

Non-uniform height semiconductor quantum rings are studied in order to determine their electronic and optical absorption properties. Theoretical modelling of the structure includes an analytical description of the non-regular multi-hilled confining potential as well as the presence of repulsive scattering centre and external crossing electric and magnetic fields. We have discussed the features of localised and extended (rotational, Aharonov–Bohm-like) states in the presence of the magnetic field. A modification of the spectrum, with the appearance of a Stark-like behaviour, and its corresponding modification related to the repulsive potential is analysed when the electric field effect is considered. In double-hilled structures, these properties of the energy spectrum are of main importance in explaining the apparent optical transparency induced within a certain range of the electric field strength. The presence of the repulsive centre is found to cause a moderate redshift of the light absorption response.

KEYWORDS:

• Quantum ring
• quantum ribbon
• Aharonov–Bohm oscillations
• non-uniform height quantum ring
• pseudopotential
• linear and non-linear properties

PACS:

• 73.21.2-b
• 75.75.1+a
• 71.70.Ej

Acknowledgments

J. H. Marin wishes to thank the Facultad de Ciencias de la Universidad Nacional de Colombia for the time in his work day to carry out the research ‘Estudio de la respuesta óptica de átomos hidrogenoides en nano-discos semiconductors (Código: 47063)’. M. E. Mora-Ramos acknowledges support and hospitality from Universidad de Medellín during the realisation of a 2019–2020 sabbatical stay. He also thanks Mexican Conacyt for partial support through CB-2018 Research grant number A1-S-8218.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

M. E. Mora-Ramos thanks Mexican Conacyt for partial support through CB-2018 Research grant number A1-S-8218.