Related Experiment Video
Updated: Feb 5, 2026
14:18
Synthesis, Assembly, and Characterization of Monolayer Protected Gold Nanoparticle Films for Protein Monolayer Electrochemistry
Published on: October 4, 2011
14.9K
Charge-tuneable biexciton complexes in monolayer WSe
Matteo Barbone1,2, Alejandro R-P Montblanch1, Dhiren M Kara1
1Cavendish Laboratory, University of Cambridge, JJ Thomson Ave., Cambridge, CB3 0HE, UK.
Nature Communications
|September 15, 2018
Summary
Researchers found evidence of complex biexciton states in transition metal dichalcogenides. This discovery enables electrical control over these multi-particle quantum phenomena.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Optics
Background:
- Monolayer transition metal dichalcogenides exhibit strong Coulomb interactions.
- Theoretical models predict complex multi-particle excitonic states.
- Experimental identification of biexcitons has been challenging due to spectral limitations.
Purpose of the Study:
- To provide direct evidence for biexciton complexes in monolayer tungsten diselenide.
- To investigate the electrical switching and optical properties of these biexciton states.
- To determine the band structure of constituent particles and analyze biexciton fine structure.
Main Methods:
- Power-dependent photoluminescence spectroscopy to identify biexciton states.
- Magneto-optical spectroscopy to resolve band states of elementary particles.
- Electrical gating for controlled switching between biexciton complexes.
Main Results:
- Direct observation of four-particle neutral biexcitons and five-particle charged biexcitons.
- Demonstration of full electrical switching between these biexciton states.
- Determination of band states and observation of a 2.5 meV fine structure splitting in neutral biexcitons.
Conclusions:
- Unveiled the nature of multi-exciton complexes in transition metal dichalcogenides.
- Established direct routes for deterministic control of many-body quantum phenomena.
- Provided a reference for future studies on biexcitons and fine structure in 2D materials.
Related Concept Videos
02:42Formal Charges
40.6K
In some cases, there are seemingly more than one valid Lewis structures for molecules and polyatomic ions. The concept of formal charges can be used to help predict the most appropriate Lewis structure when more than one reasonable structure exists.
40.6K
03:27Ions and Ionic Charges
79.2K
In ordinary chemical reactions, the nucleus — which contains the protons and neutrons of each atom and thus identifies the element — remains unchanged. Electrons, however, can be added to atoms by transfer from other atoms, lost by transfer to other atoms, or shared with other atoms. The transfer and sharing of electrons among atoms govern the chemistry of the elements. During the formation of some compounds, atoms gain or lose electrons to form electrically charged particles called...
79.2K
03:08Atomic Radii and Effective Nuclear Charge
62.2K
The elements in groups of the periodic table exhibit similar chemical behavior. This similarity occurs because the members of a group have the same number and distribution of electrons in their valence shells.
62.2K
01:11Electric Charges
22.9K
From lightning during thunderstorms to electronic devices, the phenomenon of electromagnetism is all around us. The electromagnetic force is one of the four fundamental forces of nature. It has been known to humanity in various forms for thousands of years. For example, the ancient Greek philosopher Thales of Miletus recorded his experiments on static electricity using amber and fur in the sixth century BC.
The English physicist William Gilbert studied the phenomenon of static electricity in...
The English physicist William Gilbert studied the phenomenon of static electricity in...
22.9K
01:26Charge on a Conductor
5.4K
An interesting property of a conductor in static equilibrium is that extra charges on the conductor end up on its outer surface, regardless of where they originate. Consider a hollow metallic conductor with a uniform surface charge density. Since the conductor itself is in electrostatic equilibrium, there should not be any electric field inside the conductor. Now, assume a Gaussian surface enclosing the hollow portion. Applying Gauss's law, the inner surface of the hollow conductor will not...
5.4K
03:45Formation of Complex Ions
26.1K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
26.1K