Crystal valley Hall effect

Abstract

The time-reversal symmetry is thought to be a necessary condition for realizing valley Hall effect. If the time-reversal symmetry is broken, whether the valley Hall effect can be realized has not been explored. In this letter, based on symmetry analysis and the first-principles electronic structure calculations, we demonstrate that the vally Hall effect without time-reversal symmetry can be realized in two-dimensional altermagnetic materials Fe${}_2$WSe${}_4$ and Fe${}_2$WS${}_4$. Due to crystal symmetry required, the vally Hall effect without time-reversal symmetry is called crystal vally Hall effect. In addition, under uniaxial strain, both monolayer Fe${}_2$WSe${}_4$ and Fe${}_2$WS${}_4$ can realize piezomagnetic effect. Under biaxial compressive stress, both monolayer Fe${}_2$WSe${}_4$ and Fe${}_2$WS${}_4$ will transform from altermagnetic semiconductor phase to bipolarized topological Weyl semimetal phase. Our work not only provides a new direction for exploring the novel valley Hall effect, but also provides a good platform for exploring altermagnetic semiconductors and altermagnetic topological phase transitions.

6 pages,4 figures

References in corpus (8)

• The Valley Hall Effect in MoS2 Transistors
• Crystal Thermal Transport in Altermagnetic RuO2
• Topological Superconductivity in Two-Dimensional Altermagnetic Metals
• Predictable gate-field control of spin in altermagnets with spin-layer coupling
• Quantum Anomalous Hall Effect in Antiferromagnetism
• Majorana corner modes and tunable patterns in an altermagnet heterostructure
• Creation and Manipulation of Higher-Order Topological States by Altermagnets
• Large intrinsic anomalous Hall effect in both Nb${}_2$FeB${}_2$ and Ta${}_2$FeB${}_2$ with collinear antiferromagnetism

Cited by in corpus (6)

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• Altermagnetic Weyl node-network semimetals protected by spin symmetry
• Dirac fermions in the altermagnet Ce4Sb3
• Realizing giant valley polarization effect based on monolayer altermagnets