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Stark Effects of Rydberg Excitons in a Monolayer WSe2 P-N Junction
Zhen Lian1,2, Yun-Mei Li3, Li Yan2
1Department of Physics, Carnegie Mellon University, Pittsburgh 15213, Pennsylvania, United States.
Nano Letters
|April 12, 2024
Summary
Researchers studied Rydberg excitons in two-dimensional semiconductors using photocurrent spectroscopy. An electric field shifted and mixed these exciton states, showing potential for quantum sensing applications.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Optics
Background:
- Enhanced Coulomb interaction in 2D semiconductors creates tightly bound electron-hole pairs (excitons).
- High exciton binding energy allows formation of Rydberg excitons, analogous to Rydberg atoms.
- Rydberg excitons exhibit strong interactions and sensitivity to external stimuli.
Purpose of the Study:
- To investigate Rydberg exciton resonances in monolayer WSe2.
- To explore the effects of external electric fields on Rydberg excitons.
- To demonstrate the potential of Rydberg excitons for quantum states and sensing.
Main Methods:
- Utilized photocurrent spectroscopy to probe Rydberg exciton resonances.
- Fabricated a monolayer WSe2 p-n junction using a split-gate geometry.
- Applied external in-plane electric fields to the WSe2 device.
Main Results:
- Observed significant Stark shifts in Rydberg excitons up to principal quantum number n=3.
- Demonstrated electric-field-induced mixing of different exciton orbitals.
- Showed that electric fields can brighten dark Rydberg exciton states (e.g., 3p, 3d).
Conclusions:
- External electric fields offer a powerful tool for tuning and controlling Rydberg excitons in 2D materials.
- The engineered Rydberg excitons present a promising platform for developing novel quantum states.
- This work highlights the potential of Rydberg excitons in monolayer WSe2 for advanced quantum sensing applications.
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