Reply to Comment on ‘Reply to comment on High-T _c superconductivity in H3S : pressure effects on the superconducting critical temperature and Cooper-pair distribution function’

Abstract

The so-called umklapp processes contribute to the thermal and electrical properties of solids. These are originated from the interaction between phonon-phonon and electron-phonon. In particular, the former comes from anharmonic terms. The effect of umklapp-processes in the superconductivity of high critical temperature is an open question that deserves a in-depth and detailed analysis.

Cooper-pair distribution function $$D_{cp}(\omega ,T_c)$$ for superconducting $$\hbox {D}_3\hbox {S}$$ and $$\hbox {H}_3\hbox {S}$$

“…However, the presence of umklapp process is mainly associated with the electrical resistivity 26 – 29 , which is measured in the normal state and not in the superconductor one. Our calculations were considered in the superconducting state, and Umklapp processes have not been included 13 , 30 .…”

On the use of Monkhorst–Pack scheme to evaluate superconductivity and the issue of umklapp electron–phonon interactions

“…23 Camargo-Martı ´nez and colleagues used the MP scheme to study superconductivity in H 3 S, 24 stating they had knowingly excluded umklapp contributions. 25,26 Du and colleagues used the MP scheme to study transition metallic hydrides 27 and made a similar statement. 28 We believe the practice in [21][22][23][24][25][26][27][28] amounts to an answer to the call for reducing phonon contributions to superconductivity to solve a historical difficulty.…”

“…25,26 Du and colleagues used the MP scheme to study transition metallic hydrides 27 and made a similar statement. 28 We believe the practice in [21][22][23][24][25][26][27][28] amounts to an answer to the call for reducing phonon contributions to superconductivity to solve a historical difficulty. In the BCS theory, superconductivity arises from the interactions between electrons and phonons.…”

“…Many opted to exclude umklapp phonons to deal with it. [21][22][23][24][25][26][27][28] We show it enlightens us to find an alternative option in the next section. in eqn (8) to identify the phonons allowed to pair electrons.…”

“…., perhaps an electron that undergoes the umklapp-process will contribute to electrical resistance rather than the superconducting phase''. 25 In short, they believe the umklapp process does not contribute much to superconductivity.…”