Significantly enhanced superconductivity in monolayer FeSe films on SrTiO3(001) via metallic δ-doping

Jiao，Xiaotong1,2; Dong，Wenfeng1; Shi，Mingxia1; Wang，Heng1; Ding，Cui1,3; Wei，Zhongxu1,4; Gong，Guanming1; Li，Yanan5,6; Li，Yuanzhao1; Zuo，Binjie1; Wang，Jian3,5,7,8; Zhang，Ding1; Pan，Minghu2; Wang，Lili1; Xue，Qi Kun1,3,4

2024-03-01

10.1093/nsr/nwad213

National Science Review   影响因子和分区

2095-5138

2053-714X

Superconductivity transition temperature (T) marks the inception of a macroscopic quantum phase-coherent paired state in fermionic systems. For 2D superconductivity, the paired electrons condense into a coherent superfluid state at T, which is usually lower than the pairing temperature, between which intrinsic physics including Berezinskii–Kosterlitz–Thouless transition and pseudogap state are hotly debated. In the case of monolayer FeSe superconducting films on SrTiO(001), although the pairing temperature (T) is revealed to be 65–83 K by using spectroscopy characterization, the measured zero-resistance temperature (T) is limited to 20 K. Here, we report significantly enhanced superconductivity in monolayer FeSe films by δ-doping of Eu or Al on SrTiO(001) surface, in which T is enhanced by 12 K with a narrowed transition width ΔT ∼ 8 K, compared with non-doped samples. Using scanning tunneling microscopy/spectroscopy measurements, we demonstrate lowered work function of the δ-doped SrTiO(001) surface and enlarged superconducting gaps in the monolayer FeSe with improved morphology/electronic homogeneity. Our work provides a practical route to enhance 2D superconductivity by using interface engineering.

interface superconductivity monolayer FeSe superconductivity transition temperature zero-resistance temperature δ-Doping

SCI

英语

其他

2-s2.0-85182526628

Scopus

1.State Key Laboratory of Low-Dimensional Quantum Physics,Department of Physics,Tsinghua University,Beijing,100084,China
2.School of Physics & Information Technology,Shaanxi Normal University,Xi’an,710119,China
3.Beijing Academy of Quantum Information Sciences,Beijing,100193,China
4.Department of Physics,Southern University of Science and Technology,Shenzhen,518055,China
5.International Center for Quantum Materials,School of Physics,Peking University,Beijing,100871,China
6.Department of Physics,The Pennsylvania State University,University Park,16802,United States
7.Collaborative Innovation Center of Quantum Matter,Beijing,100871,China
8.Hefei National Laboratory,Hefei,230088,China

Jiao，Xiaotong,Dong，Wenfeng,Shi，Mingxia,et al. Significantly enhanced superconductivity in monolayer FeSe films on SrTiO3(001) via metallic δ-doping[J]. National Science Review,2024,11(3).

Jiao，Xiaotong.,Dong，Wenfeng.,Shi，Mingxia.,Wang，Heng.,Ding，Cui.,...&Xue，Qi Kun.(2024).Significantly enhanced superconductivity in monolayer FeSe films on SrTiO3(001) via metallic δ-doping.National Science Review,11(3).

Jiao，Xiaotong,et al."Significantly enhanced superconductivity in monolayer FeSe films on SrTiO3(001) via metallic δ-doping".National Science Review 11.3(2024).