Enhancement of the superconductivity and quantum metallic state in the thin film of superconducting Kagome metal KV${}_3$Sb${}_5$

Abstract

Recently V-based Kagome metal attracted intense attention due to the emergence of superconductivity in the low temperature. Here we report the fabrication and physical investigations of the high quality single-crystalline thin films of the Kagome metal KV${}_3$Sb${}_5$. For the sample with the thickness of about 15 nm, the temperature dependent resistance reveals a Berezinskii-Kosterlitz-Thouless (BKT) type behavior, indicating the presence of two-dimensional superconductivity. Compared with the bulk sample, the onset transition temperature $T_c^{onset}$ and the out-of-plane upper critical field $H_{c2}$ are enhanced by 15\% and more than 10 times respectively. Moreover, the zero-resistance state is destroyed by a magnetic field as low as 50 Oe. Meanwhile, the temperature-independent resistance is observed in a wide field region, which is the hallmark of quantum metallic state. Our results provide evidences for the existence of unconventional superconductivity in this material.

5 pages, 4 figures

References in corpus (19)

• Electric Field Effect in Atomically Thin Carbon Films
• CsV${}_3$Sb${}_5$: a ${\mathbb{Z}}_2$ topological kagome metal with a superconducting ground state
• Highly crystalline 2D superconductors
• High-temperature interface superconductivity between metallic and insulating cuprates
• Unconventional Fermi surface instabilities in the Kagome Hubbard Model
• Superconductivity in the ${\mathbb{Z}}_2$ kagome metal KV${}_3$Sb${}_5$
• Double superconducting dome and triple enhancement of Tc in the kagome superconductor CsV3Sb5 under high pressure
• Three-dimensional charge density wave and robust zero-bias conductance peak inside the superconducting vortex core of a kagome superconductor CsV${}_3$Sb${}_5$
• Superconductivity and normal-state properties of kagome metal RbV3Sb5 single crystals
• Nature of unconventional pairing in the kagome superconductors AV${}_3$Sb${}_5$
• Twofold symmetry of $c$-axis resistivity in topological kagome superconductor CsV${}_3$Sb${}_5$ with in-plane rotating magnetic field
• Highly-robust reentrant superconductivity in CsV3Sb5 under pressure
• Competition of superconductivity and charge density wave in selective oxidized CsV3Sb5 thin flakes
• Charge density wave orders and enhanced superconductivity under pressure in the kagome metal CsV3Sb5
• Magnetically Induced Metallic Phase in Superconducting Tantalum Films
• High-T_c superconductivity in ultrathin Bi_2Sr_2CaCu_2O_8+x down to halfunit-cell thickness by protection with graphene
• Double-dome superconductivity under pressure in the V-based Kagome metals AV3Sb5 (A = Rb and K)
• Nodal superconductivity and superconducting domes in the topological Kagome metal CsV3Sb5
• Piezo-driven sample rotation system with ultra-low electron temperature

Cited by in corpus (4)

• AV${}_3$Sb${}_5$ Kagome Superconductors: Progress and Future Directions
• FeGe as a building block for the kagome 1:1, 1:6:6, and 1:3:5 families: hidden d-orbital decoupling of flat band sectors, effective models and interaction Hamiltonians
• Kagome Materials I: SG 191, ScV${}_6$Sn${}_6$. Flat Phonon Soft Modes and Unconventional CDW Formation: Microscopic and Effective Theory
• Unique quantum metallic state in the titanium sesquioxide heterointerface superconductor