Electronic properties of correlated kagomé metals AV3Sb5 (A = K, Rb, and Cs): A perspective

Abstract

Following the discovery of a new family of kagomé prototypical materials with structure AV 3 Sb 5 (A ¼ K, Rb, and Cs), there has been a heightened interest in studying the correlation-driven electronic phenomena in these kagomé lattice systems. The study of these materials has gone beyond magneto-transport measurements to reveal exciting features such as Dirac bands, anomalous Hall effect, bulk superconductivity with T c 0:9À2:5 K, and the observation of charge density wave instabilities, suggesting an intertwining of topological physics and new quantum orders. Moreover, very recent works on numerous types of experiments have appeared further examining the unconventional superconductivity and the exotic electronic states found within these kagomé materials. Theories on the strong interactions that play a role in these systems have been proposed to shed light on the nature of these topological charge density waves. In this brief review, we summarize these recent experimental findings and theoretical proposals and envision the materials as new platforms to study the interplay between topological physics and strongly correlated electronic systems.

Electronic Properties and Phase Transition in the Kagome Metal Yb0.5Co3Ge3

“…The Kagome lattice is made up of hexagons that are surrounded on their edges by equilateral triangles. Analogous to the honeycomb lattice, the Kagome lattice is an important structure for realizing a quantum spin liquid state due to its inherent geometric frustration; some of the leading spin liquid candidates are Kagome insulators. , Recently, however, Kagome metals have gained attention due to the realization of both topological Dirac electrons and flat bands and van Hove singularities resulting in strong electron correlation. − Materials in the AV 3 Sb 5 (A = K, Cs, and Rb) family − have shown both topological bands with low effective mass, a large anomalous Hall effect, , and a cascade of charge density wave (CDW) − orderings and superconductivity − as temperature is lowered.…”

Exploration of the physical properties of the newly synthesized kagome superconductor LaIr3Ga2 using different exchange–correlation functionals

“…The fact that A i values deviate significantly from unity for all the functionals implies that the LaIr 3 Ga 2 kagome superconductor is anisotropic (Table 3). The values of A 1 and A 2 differ by a significant amount from unity; 1 thus, significant shear anisotropy is observed in the {100} and {010} shear planes. The anisotropy of linear compressibility is also presented in Table 3.…”

“…kagome materials have disclosed an impressive platform for exploring novel electronic ground states. These materials display nontrivial band topology, 1 strong electronic correlations, 1 topological quantum states, [2][3][4][5][6] charge density waves, [7][8][9][10][11][12][13][14][15] the absence of local moments, 16 Majorana zero modes, 7 edge super-current, 17 and unconventional superconductivity. 18 Flat bands, Dirac cones, and van Hove singularities (VHSs) are also seen in kagome materials.…”

Multiple superconducting phases in heavy-fermion metals

“…Although HFs have been the focus of this work, it is important to note that multiple superconducting phases have also been observed in YBa 2 Cu 3 O y (Grissonnanche et al, 2014), LaFeAsO 1-x (H/F) x (Iimura et al, 2012), BaTi 2 (Sb 1-x Bi x ) 2 O (Zhai et al, 2013), and very recently, in the kagome superconductors CsV 3 Sb 5 Nguyen and Li, 2022) and RbV 3 Sb 5 (Guguchia et al, 2022). As illustrated here, recent advances in experimental techniques have provided a much-improved characterization of sample properties in transport, thermodynamic, and various spectroscopies.…”