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Multiband charge density wave exposed in a transition metal dichalcogenide.
Árpád Pásztor1, Alessandro Scarfato2, Marcello Spera2
1Department of Quantum Matter Physics, Université de Genève, 24 quai Ernest Ansermet, CH-1211, Geneva 4, Switzerland. arpad.pasztor@unige.ch.
Nature Communications
|October 16, 2021
Summary
Researchers discovered a multiband charge density wave (CDW) in 2H-NbSe2, involving two electronic bands. This finding, using scanning tunnelling microscopy, reveals complex CDW behavior previously overlooked in multiband systems.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Surface Science
Background:
- Multiband electronic systems can exhibit complex phenomena.
- While multiband superconductivity is well-studied, multiband charge density waves (CDWs) remain underexplored.
- Electronic instabilities gain complexity in the presence of multiple electronic bands.
Purpose of the Study:
- To investigate the possibility of multiband charge density waves (CDWs) in 2H-NbSe2.
- To explore the behavior of CDWs in systems with multiple electronic bands.
- To provide evidence for a CDW involving more than one electronic band.
Main Methods:
- Utilizing energy-dependent scanning tunnelling microscopy (STM) topography.
- Employing a simplified model for charge modulations.
- Performing self-consistent calculations of the CDW gap.
Main Results:
- Evidence for a multiband CDW was found in 2H-NbSe2.
- The CDW involves the opening of a gap on both the inner and outer electronic bands near the K-point.
- Spatially out-of-phase charge modulations were detected due to electrons on these two bands.
Conclusions:
- The study confirms the existence of a multiband CDW in 2H-NbSe2.
- This multiband CDW exhibits unique characteristics, including out-of-phase modulations between bands.
- The findings highlight the importance of considering multiband effects in understanding CDWs.
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