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Cone-Shell Quantum Structures in Electric and Magnetic Fields as Switchable Traps for Photoexcited Charge Carriers
Christian Heyn1, Leonardo Ranasinghe1, Ahmed Alshaikh1
1Center for Hybrid Nanostructures (CHyN), University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
Nanomaterials (Basel, Switzerland)
|May 27, 2023
Summary
Optical emission in cone-shell quantum structures (CSQS) can be switched between bright and dark states by adjusting electric and magnetic fields. This tunable control over optical properties offers potential for trapping photoexcited charge carriers.
Area of Science:
- Quantum physics
- Condensed matter physics
- Nanotechnology
Background:
- Cone-shell quantum structures (CSQS) exhibit unique electronic properties.
- Electric fields can transform hole probability density in CSQS into a tunable quantum ring.
- The Fock-Darwin model describes magnetic field effects in quantum dots.
Purpose of the Study:
- Investigate the optical emission of CSQS under combined electric and magnetic fields.
- Analyze the influence of magnetic fields on hole energy states in CSQS.
- Explore the transition between bright and dark optical states.
Main Methods:
- Numerical simulations of CSQS under vertical electric (F) and magnetic (B) fields.
- Analysis of hole probability density and energy levels.
- Comparison with the Fock-Darwin model.
Main Results:
- Simulated hole energy dependence on the magnetic field deviates from the Fock-Darwin model.
- Exited states (lh>0) can have lower energy than the ground state (lh=0).
- States with lh>0 are optically dark due to selection rules.
Conclusions:
- Switching between bright (lh=0) and dark (lh>0) optical states is achievable by tuning F or B fields.
- This controllable switching is valuable for trapping photoexcited charge carriers.
- The shape of CSQS influences the fields needed for bright-dark state transitions.
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