1State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084 2Collaborative Innovation Center of Quantum Matter, Beijing 100084
Abstract：We report scanning tunneling microscopy investigation on epitaxial ultrathin films of pyrite-type copper disulfide. Layer-by-layer growth of CuS$_{2}$ films with a preferential orientation of (111) on SrTiO$_{3}$(001) and Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ substrates is achieved by molecular beam epitaxy growth. For ultrathin films on both kinds of substrates, we observe symmetric tunneling gap around the Fermi level that persists up to $\sim$15 K. The tunneling gap degrades with either increasing temperature or increasing thickness, suggesting new matter states at the extreme two-dimensional limit.
Navarro-Moratalla E, Island J O, Mañas Valero S, Pinilla-Cienfuegos E, Castellanos-Gomez A, Quereda J, Rubio-Bollinger G, Chirolli L, Silva-Guillen J A, Agrait N, Steele G A, Guinea F, van der Zant H S and Coronado E 2016 Nat. Commun.7 11043
[3]
Wang Q Y, Li Z, Zhang W H, Zhang Z C, Zhang J S, Li W, Ding H, Ou Y B, Deng P, Chang K, Wen J, Song C L, He K, Jia J F, Ji S H, Wang Y Y, Wang L, Chen X, Ma X C and Xue Q K 2012 Chin. Phys. Lett.29 037402
2018, Vol. 35 
