Electronic inhomogeneity and phase fluctuation in one-unit-cell FeSe films

Zhao，Dapeng1; Cui，Wenqiang1,2; Liu，Yaowu2; Gong，Guanming2; Zhang，Liguo1; Jia，Guihao2; Zang，Yunyi1; Hu，Xiaopeng2; Zhang，Ding1,2,3; Wang，Yilin4; Li，Wei2,3; Ji，Shuaihua2,3; Wang，Lili2,3; He，Ke1,2,3; Ma，Xucun2,3; Xue，Qi Kun1,2,3,5

2024-12-01

10.1038/s41467-024-47350-0

Nature Communications   影响因子和分区

2041-1723

One-unit-cell FeSe films on SrTiO substrates are of great interest owing to significantly enlarged pairing gaps characterized by two coherence peaks at ±10 meV and ±20 meV. In-situ transport measurement is desired to reveal novel properties. Here, we performed in-situ microscale electrical transport and combined scanning tunneling microscopy measurements on continuous one-unit-cell FeSe films with twin boundaries. We observed two spatially coexisting superconducting phases in domains and on boundaries, characterized by distinct superconducting gaps (Δ~15 meV vs. Δ~10 meV) and pairing temperatures (T~52.0 K vs. T~37.3 K), and correspondingly two-step nonlinear V~I behavior but a concurrent Berezinskii–Kosterlitz–Thouless (BKT)-like transition occurring at T~28.7 K. Moreover, the onset transition temperature T~54 K and zero-resistivity temperature T~31 K are consistent with T and T, respectively. Our results indicate the broadened superconducting transition in FeSe/SrTiO is related to intrinsic electronic inhomogeneity due to distinct two-gap features and phase fluctuations of two-dimensional superconductivity.

SCI

英语

其他

2-s2.0-85190804826

Scopus

1.Beijing Academy of Quantum Information Sciences,Beijing,100193,China
2.State Key Laboratory of Low-Dimensional Quantum Physics,Department of Physics,Tsinghua University,Beijing,100084,China
3.Frontier Science Center for Quantum Information,Beijing,100084,China
4.School of Integrated Circuits,Shandong Technology Center of Nanodevices and Integration,State Key Laboratory of Crystal Materials,Shandong University,Jinan,250100,China
5.Department of Physics,Southern University of Science and Technology,Shenzhen,518055,China

Zhao，Dapeng,Cui，Wenqiang,Liu，Yaowu,et al. Electronic inhomogeneity and phase fluctuation in one-unit-cell FeSe films[J]. Nature Communications,2024,15(1).

Zhao，Dapeng.,Cui，Wenqiang.,Liu，Yaowu.,Gong，Guanming.,Zhang，Liguo.,...&Xue，Qi Kun.(2024).Electronic inhomogeneity and phase fluctuation in one-unit-cell FeSe films.Nature Communications,15(1).

Zhao，Dapeng,et al."Electronic inhomogeneity and phase fluctuation in one-unit-cell FeSe films".Nature Communications 15.1(2024).