Subgap two-particle spectral weight in disordered s -wave superconductors: Insights from mode coupling approach
| Autor: | Prathyush P. Poduval, Abhisek Samanta, Prashant Gupta, Nandini Trivedi, Rajdeep Sensarma |
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| Rok vydání: | 2022 |
| Předmět: |
Superconductivity (cond-mat.supr-con)
Condensed Matter - Strongly Correlated Electrons Strongly Correlated Electrons (cond-mat.str-el) Condensed Matter - Superconductivity FOS: Physical sciences Disordered Systems and Neural Networks (cond-mat.dis-nn) Condensed Matter - Disordered Systems and Neural Networks |
| Zdroj: | Physical Review B. 106 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.106.064512 |
| Popis: | We study the two-particle spectral functions and collective modes of weakly disordered superconductors using a disordered attractive Hubbard model on square lattice. We show that the disorder induced scattering between collective modes leads to a finite subgap spectral weight in the long wavelength limit. In general, the spectral weight is distributed between the phase and the Higgs channels, but as we move towards half-filling the Higgs contribution dominates. The inclusion of the density fluctuations lowers the frequency at which this mode occurs, and results in the phase channel gaining a larger contribution to this subgap mode. Near half-filling, the proximity of the system to the charge density wave (CDW) instability leads to strong fluctuations of the effective disorder at the commensurate wave-vector ($[\pi,\pi]$). We develop an analytical mode coupling approach where the pure Goldstone mode in the long wavelength limit couples to the collective mode at $[\pi,\pi]$. This provides insight into the location and distribution of the two-particle spectral weights between the Higgs and the phase channels. |
| Databáze: | OpenAIRE |
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