Ultraquantum magnetoresistance in Kramers Weyl semimetal candidate $\beta$-Ag2Se

Abstract

The topological semimetal $\beta$-Ag2Se features a Kramers Weyl node at the origin in momentum space and a quadruplet of spinless Weyl nodes, which are annihilated by spin-orbit coupling. We show that single crystalline $\beta$-Ag2Se manifests giant Shubnikov-de Haas oscillations in the longitudinal magnetoresistance which stem from a small electron pocket that can be driven beyond the quantum limit by a field less than 9 T. This small electron pocket is a remainder of the spin-orbit annihilatedWeyl nodes and thus encloses a Berry-phase structure. Moreover, we observed a negative longitudinal magnetoresistance when the magnetic field is beyond the quantum limit. Our experimental findings are complemented by thorough theoretical band structure analyses of this Kramers Weyl semimetal candidate, including first-principle calculations and an effective k*p model.

A new version based on arXiv:1502.02324

References in corpus (2)

• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Quantum Transport in Topological Semimetals under Magnetic Fields

Cited by in corpus (14)

• Discovery of topological chiral crystals with helicoid arc states
• Weyl, Dirac and high-fold chiral fermions in topological quantum materials
• Topological Materials Discovery from Crystal Symmetry
• Twofold quadruple Weyl nodes in chiral cubic crystals
• Chiral anomalies in 3D spin-orbit coupled metals: electrical, thermal, and gravitational anomaly
• Transverse Peierls Transition
• Kramers-Weyl fermions in the chiral charge density wave material (TaSe${}_4$)${}_2$I
• Temperature induced first order electronic topological transition in $\beta$-Ag${}_2$Se
• Conservation of chirality at a junction between two Weyl semimetals
• Disentangling contributions to longitudinal magnetoconductivity for Kramers-Weyl nodes
• Magnetoresistance in the Extreme Quantum Limit: Field-Induced Crossover to the Unitarity Limit
• Giant and Linear Magnetoresistance in Liquid Metals at Ambient Temperature
• Spinor-dominated magnetoresistance driven by the topological phase transition in $\beta$-Ag${}_2$Se
• Theory for the negative longitudinal magnetoresistance in the quantum limit of Kramers Weyl semimetals