Electron-boson spectral density functions of cuprates obtained from optical spectra via machine learning

Abstract

The electron-boson spectral density (or glue) function can be obtained from measured optical scattering rate by solving a generalized Allen formula, which relates the two quantities with an integral equation and is an inversion problem. Thus far, numerical approaches, such as the maximum entropy method (MEM) and the least squares fitting method, have been applied for solving the generalized Allen formula. Here, we developed a new method to obtain the glue functions from the optical scattering rate using a machine learning approach (MLA). We found that the MLA is more robust against random noise compared with the MEM. We applied the new developed MLA to experimentally measured optical scattering rates and obtained reliable glue functions in terms of their shapes including the amplitudes. We expect that the MLA can be a useful and rapid method for solving other inversion problems, which may contain random noise.

14 pages, 4 figures

References in corpus (6)

• Optical determination of the relation between the electron-boson coupling function and the critical temperature in high T${}_c$ cuprates
• Spin Dynamics in Cuprates: Optical Conductivity of HgBa2CuO4
• Bosonic spectral density of epitaxial thin-film La1.83Sr0.17CuO4 superconductors from infrared conductivity measurements
• Doping dependent optical properties of Bi2201
• Fermi surface arcs and the infrared conductivity of underdoped YBa${}_2$Cu${}_3$O${}_{6.50}$
• Reverse process of usual optical analysis of boson-exchange superconductors: impurity effects on $s$- and $d$-wave superconductors