Thickness-dependent oscillation of the superconducting Tc in ultrathin NbC films: A first-principles study

Chang-Jiang Wu; Jian-Feng Zhang; Pei-Han Sun; Huan-Cheng Yang; Zhong-Yi Lu; Kai Liu

doi:10.1103/PhysRevB.108.115161

← Back to search

Thickness-dependent oscillation of the superconducting Tc in ultrathin NbC films: A first-principles study

Chang-Jiang Wu, Jian-Feng Zhang, Pei-Han Sun, Huan-Cheng Yang, Zhong-Yi Lu, Kai Liu

DOI 10.1103/PhysRevB.108.115161 · 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 dimensionality effect on superconductivity has been a long-term interesting topic. Here we have systematically investigated the electronic and superconducting properties of ultrathin NbC films by using first-principles electronic structure calculations. We find that the superconducting transition temperatures of ultrathin NbC films show an interesting thickness-dependent oscillation, whose amplitude can reach as large as 10 K. Notably, the superconducting Tc of trilayer NbC film is predicted to be 16.8 K, even higher than that (11.5 K) of bulk NbC. Further analyses indicate that the ultrathin NbC films with relatively high superconducting Tc's all have strong phonon softening and enhanced electron-phonon coupling, for which the special phonon modes and electronic states as well as their real-space patterns are clarified. Our results provide an insight for modulating the superconductivity of transition metal carbides with the reduced dimensionality.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
NbC Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	16.8	Pressure not reported	unknown
NbC Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	11.5	Pressure unresolved	unknown
Nb Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	9.2	Pressure unresolved	unknown
NbN Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	15.25	Pressure not reported	unknown
Nb3Sn Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	18.05	Pressure not reported	unknown
Nb3Al0.8Ge0.2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	20	Pressure not reported	unknown
Nb3Ga Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	20.3	Pressure not reported	unknown
Nb3Ge Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	23.2	Pressure not reported	unknown