While CDWs and superconductivity can coexist in some materials, their interaction can be either cooperative or antagonistic. In some cases, the presence of a CDW can enhance superconductivity, while in other cases it can suppress it.
Cooperative effects
One possible scenario is that the formation of a CDW can lead to an increase in the electron-phonon coupling, which is a key factor in conventional superconductivity. This enhanced coupling can strengthen the attractive interactions between electrons and phonons, thereby promoting the formation of Cooper pairs and increasing the critical temperature for superconductivity.
Additionally, in certain materials, the periodic charge density modulation associated with a CDW can open up gaps in the Fermi surface, resulting in the formation of new electron pockets. These new electron pockets can contribute to the overall superconducting properties of the material.
Antagonistic effects
On the other hand, the presence of a CDW can also have detrimental effects on superconductivity. For instance, the periodic potential associated with a CDW can lead to the scattering of Cooper pairs, disrupting their coherence and hindering the superconducting state.
Furthermore, in some cases, the formation of a CDW can introduce additional electronic states that compete with the superconducting ground state, making it energetically less favorable. This can lead to a suppression of superconductivity or even its complete disappearance.
The interplay between CDWs and superconductivity is highly material-dependent and can vary widely depending on the specific properties and characteristics of the system. Therefore, it is necessary to study each material individually to understand the intricate relationship between these two phenomena.
