← Back to search

Role of SrTiO3 phonon penetrating into thin FeSe films in the enhancement of superconductivity

Shuyuan Zhang, Jiaqi Guan, Xun Jia, Bing Liu, Weihua Wang, Fangsen Li, Lili Wang, Xucun Ma, Qikun Xue, Jiandi Zhang, E. W. Plummer, Xuetao Zhu, Jiandong Guo

DOI 10.1103/PhysRevB.94.081116 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

The significant role of interfacial coupling in the enhancement of superconductivity in FeSe films on SrTiO3 has been widely recognized, but the explicit origin of this coupling is yet to be identified. Here, by surface phonon measurements using high-resolution electron energy loss spectroscopy, we found the electric field generated by Fuchs-Kliewer (F-K) phonon modes of SrTiO3 can penetrate into FeSe films and strongly interact with the electrons therein. The mode-specific electron-phonon coupling constant for the ∼92 meV F-K phonon is ∼0.25 in single-layer FeSe on SrTiO3. With increasing FeSe thickness, the penetrating field intensity decays exponentially, which matches well the observed exponential decay of the superconducting gap. It is unambiguously shown that the SrTiO3 F-K phonon penetrating into FeSe is essential for interfacial superconductivity enhancement.

Source-reported materials — not catalogue approval

FormulaReported Tc (K)Pressure (GPa)Type
FeSe

Archive — visibility unverified

Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.

65Pressure not reportedunknown
FeSe

Archive — visibility unverified

Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.

65Pressure not reportedunknown
FeSe

Archive — visibility unverified

Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.

8Pressure not reportedunknown

Similar papers