Mixed dimensional transport in CsV$_3$Sb$_5$ single crystals

Abstract

The observation of superconductivity and charge order in the Kagome-net compound CsV 3 Sb 5 has raised interest in its possible topological superconducting state. Key to this puzzle, as in any structurally layered conductor, is its effective electronic dimensionality. Here we present transport evidence for its dual nature, the coexistence of high-mobility quasi-two-dimensional Fermi surface sheets with small closed pockets that are crucial for the overall mixed dimensionality of this metal.It reflects in an unusual complete vanishing of magnetoresistance above T CDW , which increases by a factor of a million upon entering the ordered state. Quantum oscillations further confirm the presence of multiple, closed 3D pockets coexisting with the main cylinders -which take a central role in the out-of-plane transport. These results caution that the main Kagome physics may be altered when these planes are stacked in a real 3D material.

Switchable chiral transport in charge-ordered kagome metal CsV3Sb5

“…To truly obtain symmetry lowering from spontaneous symmetry breaking, it is critical to avoid any accidental strain fields that may break the symmetry explicitly. To do so, we decouple the crystalline bar mechanically as much as possible from its supporting substrate 31 (Fig. 2a).…”

“…On the basis of the crystalline structure, we have calculated the band structure of CsV 3 Sb 5 by density functional theory using the Quantum Espresso package 41 , the details of which can be found in ref. 31 . The obtained electronic structure features multiple Dirac nodal lines lifted by spin-orbit coupling, leaving only symmetry-protected Dirac nodes at L points.…”

“…The spring constant of the SiN x spring for device S1 is estimated as 125 N m −1 from finite element simulations 31 (COMSOL), the total pressure can be calculated as:…”