Distinct pressure evolution of superconductivity and charge density wave in kagome superconductor CsV3Sb5 thin flakes

It is intriguing to explore the coexistence and (or) competition between\ncharge-density-wave (CDW) and superconductivity (SC) in many correlated\nelectron systems, such as cuprates, organic superconductors and\ndichacolgenides. Among them, the recently discovered $\\mathbb{Z} _2$\ntopological kagome metals AV$_3$Sb$_5$ (A=K, Rb, Cs) serve as an ideal platform\nto study the intricate relation between them. Here, we report the electrical\nresistance measurements on CsV$_3$Sb$_5$ thin flakes ($\\approx$ 60 nm) under\nhydrostatic pressure up to 2.12 GPa to compare its pressure phase diagram of\nCDW and SC with its bulk form. Even though the CDW transition temperature\n(T$_{CDW}$) in CsV$_3$Sb$_5$ thin flakes is still monotonically suppressed\nunder pressure and totally vanishes at P$_2$=1.83 GPa similar to the bulk, the\nsuperconducting transition temperature (T$_c$) shows an initial decrease and\nconsequent increase up to its maximum $\\sim$ 8.03 K at P$_2$, in sharp contrast\nwith the M-shaped double domes in the bulk CsV$_3$Sb$_5$. Our results suggest\nthe important role of reduced dimensionality on the CDW state and its interplay\nwith the SC, offering a new perspective to explore the exotic nature of\nCsV$_3$Sb$_5$.\n