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Optical valley separation in two-dimensional semimetals with tilted Dirac cones
Andrew Wild1, Eros Mariani2, M E Portnoi3
1Physics and Astronomy, University of Exeter, Stocker Road, Exeter, EX4 4QL, United Kingdom. A.Wild@exeter.ac.uk.
Scientific Reports
|November 6, 2023
Summary
Researchers demonstrate optical valley separation in 2D semimetals, enabling new valleytronic devices. This phenomenon uses tilted Dirac cones for information encoding across various light frequencies.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Information Science
Background:
- Valley quantum number in quasiparticles offers a basis for information encoding in valleytronics.
- Two-dimensional (2D) materials with Dirac cones are promising for electronic applications.
Purpose of the Study:
- To investigate optical valley separation in 2D semimetals with tilted Dirac cones.
- To explore the potential for broadband optovalleytronic devices operating at low photon frequencies.
Main Methods:
- Theoretical analysis of electronic band structures in 2D semimetals.
- Investigating optovalleytronic phenomena in systems with intact symmetries and gapless Dirac cones.
- Predicting tunable valley separation in 8-Pmmn borophene using infrared photons.
Main Results:
- Spatial separation of valley carriers demonstrated in 2D semimetals under illumination.
- Optovalleytronic effect observed in systems with intact inversion and time-reversal symmetry.
- Tunable optical valley separation achieved at low photon frequencies (infrared, terahertz) via Pauli blocking.
Conclusions:
- 2D tilted Dirac cone semimetals are a viable platform for tunable, broadband optovalleytronic applications.
- The findings pave the way for novel valleytronic devices utilizing optical control.
- Demonstrated feasibility of optical valley separation at room temperature in specific 2D materials.
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