2024/08/22 by Debraj Bose, Bose, Debraj, Sankha Subhra Bakshi +3 · 1 citation
Materials Science · #Electronic and Structural Properties of Oxides #FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2408.12542
openalex publication_date 2024/08/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Recent experiments on nanoclusters of silver (Ag) embedded in a gold (Au) matrix reveal a huge increase in both the zero temperature resistivity and the coefficient of the ``T linear'' thermal resistivity with increasing volume fraction of Ag. A fraction f ∼ 50% of Ag leads to a factor of 20 increase in the residual resistivity, and a 40 fold enhancement in the coefficient of linear T resistivity, with respect to Au. Since Au and Ag both have weak electron-phonon coupling we surmise that the huge enhancements arise from a moderately large electron-phonon coupling that may emerge at the Ag-Au interface. We construct nanocluster configurations for varying f in two dimensions, define a Holstein model on it with weak coupling on the `interior' sites and a strong coupling on the interfacial sites, and solve the model through exact diagonalisation based Langevin dynamics. Computing the resistivity, we observe a large T=0 increase with f and also a linear T enhancement factor of ∼ 30. While the enhancement factors are parameter choice dependent, our key qualitative result is that the interface physics is inhomogeneous, with widely varying distortions, and different segments of the interface dictate the residual resistivity and the thermal scattering.