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Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
Published on: December 5, 2015
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Valleytronics in bulk MoS2 with a topologic optical field
Igor Tyulnev1, Álvaro Jiménez-Galán2,3, Julita Poborska1
1ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Spain.
Nature
|April 24, 2024
Summary
Researchers demonstrate non-resonant optical control of electron valley polarization in bulk MoS2. This universal method uses shaped light pulses to switch electronic topology, enabling faster, more efficient valleytronic devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Information
Background:
- Electron valley degree of freedom offers potential for energy-efficient information storage and quantum processing.
- Current methods for valley control face challenges like symmetry requirements and energy dissipation.
Purpose of the Study:
- To demonstrate all-optical, non-resonant control of valley polarization in bulk MoS2.
- To overcome limitations of monolayer-specific or engineered material requirements for valley control.
Main Methods:
- Utilized spin angular momentum-shaped trefoil optical pulses for control.
- Exploited transient breaking of time and space inversion symmetry via phase rotation.
- Confirmed valley polarization through second-harmonic generation of a non-collinear optical probe pulse.
Main Results:
- Achieved all-optical, non-resonant valley polarization control in bulk MoS2, a centrosymmetric material.
- Demonstrated that this control is independent of material thickness, applicable to bulk systems.
- Validated the universal nature of the non-resonant valley control method.
Conclusions:
- Direct optical control of valley degree of freedom is feasible beyond monolayer structures.
- Non-resonant valley control is universal and operates at optical speeds.
- This technique enables the development of efficient multimaterial valleytronic devices for quantum coherent applications.
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