Interplay between the charge densitiy waves and superconductivity in transition metal chalcogenides

• Applicant: Dr. Sergey Borisenko
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2007 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 58734343

The density waves in solids are a fascinating example of the self-organization of the valence electronswhich leads to significant modifications of the physical properties of the material. It is currentlyunder intense debates whether the charge and/or spin-density waves and their fluctuationsare indispensable ingredients for the high-temperature superconductivity in the cuprates and novelFe-superconductors. Our results obtained within the framework of the previous proposal stronglysuggest that while the origin of the charge-density waves in the most representative chalcogenidesand other compounds is related to the nesting instability of the electronic structure, the electronicorder itself is important for the superconductivity.The aim of this proposal is to clarify the origin of the interplay between CDW and superconductivityand to extend the developed approach to the phase diagrams of the chalcogenides with lowcritical transition temperatures using modern ARPES and its combination with other techniques.At this, a variety of material-specific issues, such as formation of the Dirac cones in doped TaSe2or detection of the predicted amplitude mode in NbSe2 will be addressed as well.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Bernd Büchner