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Updated: Dec 12, 2025
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Using Microwave and Macroscopic Samples of Dielectric Solids to Study the Photonic Properties of Disordered Photonic Bandgap Materials
Published on: September 26, 2014
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Pseudogap and Weak Multifractality in 2D Disordered Mott Charge-Density-Wave Insulator
Jianhua Gao1, Jae Whan Park1, Kiseok Kim2
1Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Korea.
Nano Letters
|August 14, 2020
Summary
We studied Se-substituted 1T-TaS2 and found a pseudogap replacing the Mott gap, suggesting a correlated metallic state. This offers new insights into superconductivity in 2D materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Superconductivity
Background:
- 1T-TaS2 exhibits a Mott-charge-density-wave (Mott-CDW) state, a unique electronic phase.
- Superconductivity emerges in this material, but its origin remains debated.
- Selenium (Se) substitution is explored to tune the electronic properties.
Purpose of the Study:
- Investigate the electronic states of Se-substituted 1T-TaS2.
- Understand the relationship between the pseudogap, Mott gap, and superconductivity.
- Clarify the role of disorder in the emerging correlated metallic state.
Main Methods:
- Scanning tunneling microscopy/spectroscopy (STM/STS) was employed.
- Spatially resolved STS measurements were performed.
- Statistical analysis of local density of states (LDOS) was conducted.
Main Results:
- A pseudogap was observed, replacing the Mott gap while CDW gaps remained.
- The pseudogap showed a global presence, independent of local Se concentration variations.
- Enhanced correlation length of LDOS at the Fermi energy and weak multifractal behavior of wave functions were detected.
Conclusions:
- The findings suggest a correlated metallic state induced by disorder in Se-substituted 1T-TaS2.
- This provides new insights into the mechanism of emerging superconductivity in 2D materials.
- The study highlights the complex interplay between CDW order, disorder, and superconductivity.
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