"Electronic and phononic properties of a two-dimensional electron gas coupled to dipolar phonons via small-momentum-transfer scattering"

Zi-Xiang Li: T. P. Devereaux, and Dung-Hai Lee; Physical Review B, 12/03/19.

Additional Authors: T. P. Devereaux, and Dung-Hai Lee

Abstract:

We study the electron and phonon spectral functions as well as superconductivity for a two-dimensional electron gas coupled to dipolar phonons via small-momentum-transfer scattering. The results reported here are obtained through sign-problem-free quantum Monte Carlo simulation. Hence, aside from modeling there are no further approximations. Our results can be relevant to the high-temperature superconductor at the interface between a unit-cell-thick FeSe and SrTiO3. Our results give support to the interpretation that the observed replica band in unit-cell-thick FeSe on SrTiO3 is due to the small-momentum transfer interaction between the FeSe electrons and a branch of polar STO phonons. Moreover, we conclude that while the small-momentum electron-phonon interaction can not induce strong Cooper pairing by itself, it can enhance the Cooper pairing triggered by other pairing interactions.