Field-tuned chiral transport in charge-ordered CsV$_3$Sb$_5$

Abstract

When conductors differ from their mirror image, their chirality is reflected in the electron states and their dynamics. Conventionally, mirror symmetries are broken by the atomic structure of crystals and imprint their low symmetry onto the itinerant electron states. Unusual transport properties are a hallmark of chiral crystals, such as a non-linear electric response known as electronic magneto-chiral ansiotropy (eMChA). Here we report such a transport signature in the centro-symmetric layered Kagome metal CsV 3 Sb 5 , observed via second harmonic generation under magnetic field. We observe the signal in a charge-ordered phase of the material, which has been proposed to be a loop-current phase with spontaneously broken mirror symmetries. While charge ordering sets in at T CDW ∼ 94 K, the eMChA transport becomes significant only at temperatures below T ∼ 34 K, indicative of further evolutions of this ordered phase upon lowering the temperature. Crucially, we demonstrate that the nonlinear magnetotransport can be switched by small out-of-plane fields, in accordance with recent tunneling microscopy experiments. Unlike structurally chiral materials, our results demonstrate how the electronic chirality of a metal can be tuned and even abruptly switched by small changes in magnetic fields alone -a prerequisite for their applications in chiral electronics.

Incommensurate charge-stripe correlations in the kagome superconductor CsV3Sb5-xSnx

“…Charge correlations and the nature of charge density wave (CDW) order within the new class of AV 3 Sb 5 (A=K, Rb, Cs) kagome superconductors [1][2][3][4] are hypothesized to play a crucial role in the anomalous properties of these compounds. Hints of pair density wave superconductivity [5,6] as well as signatures of orbital magnetism [7][8][9][10] in these compounds are all born out of a central CDW state [11][12][13]. The CDW order parameter itself is theorized to host both primary, real and secondary, imaginary components [14], each of which is thought to play a role in the anomalous properties observed in AV 3 Sb 5 compounds.…”

Incommensurate charge-stripe correlations in the kagome superconductor CsV$_3$Sb$_{5-x}$Sn$_x$

“…Charge correlations and the nature of charge density wave (CDW) order within the new class of AV 3 Sb 5 (A=K, Rb, Cs) kagome superconductors [1][2][3][4] are hypothesized to play a crucial role in the anomalous properties of these compounds. Hints of pair density wave superconductivity [5,6] as well as signatures of orbital magnetism [7][8][9][10] in these compounds are all born out of a central CDW state [11][12][13]. The CDW order parameter itself is theorized to host both primary, real and secondary, imaginary components [14], each of which thought to play a role in the anomalous properties observed in AV 3 Sb 5 compounds.…”

Charge-loop current order and Z3 nematicity mediated by bond-order fluctuations in kagome metal AV3Sb5 (A=Cs,Rb,K)

“…More recently, the non-trivial time reversal symmetry breaking (TRSB) order at T TRSB attracts considerable attention. The magneto-chiral anisotropy observed by STM [6,14] strongly indicates the emergence of the chiral charge-loop-current (cLC) inside the BO phase. The Kerr rotation measurements suggest the appearance of the TRSB state at T ∼ T BO .…”

“…The Kerr rotation measurements suggest the appearance of the TRSB state at T ∼ T BO . On the other hand, the TRSB amplitude grows prominent at T ≈ 35 K < T BO according to the muon spin relaxation (µSR) studies [15][16][17] and the field-tuned chiral transport study [14]. The chiral cLC is driven by the additional odd-parity hopping integral δt c ij (=imaginary), and the accompanied topological charge-current [18] give the giant anomalous Hall effect (AHE) below T ≈ 35 K [19,20].…”