Anomalies in the temperature evolution of Dirac states in the topological crystalline insulator SnTe

AbstractKnowledge of magnetic symmetry is vital for exploiting nontrivial surface states of magnetic topological materials. EuIn2As2 is an excellent example, as it is predicted to have collinear antiferromagnetic order where the magnetic moment direction determines either a topological-crystalline-insulator phase supporting axion electrodynamics or a higher-order-topological-insulator phase with chiral hinge states. Here, we use neutron diffraction, symmetry analysis, and density functional theory results to demonstrate that EuIn2As2 actually exhibits low-symmetry helical antiferromagnetic order which makes it a stoichiometric magnetic topological-crystalline axion insulator protected by the combination of a 180∘ rotation and time-reversal symmetries: $${C}_{2}\times {\mathcal{T}}={2}^{\prime}$$ C 2 × T = 2 ′ . Surfaces protected by $${2}^{\prime}$$ 2 ′ are expected to have an exotic gapless Dirac cone which is unpinned to specific crystal momenta. All other surfaces have gapped Dirac cones and exhibit half-integer quantum anomalous Hall conductivity. We predict that the direction of a modest applied magnetic field of μ0H ≈ 1 to 2 T can tune between gapless and gapped surface states.

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Pressure-induced phase transitions in the topological crystalline insulator SnTe and its comparison with semiconducting SnSe: Raman and first-principles studies

Physical Review B ◽

10.1103/physrevb.101.155202 ◽

2020 ◽

Vol 101 (15) ◽

Cited By ~ 3

Author(s):

Sukanya Pal ◽

Raagya Arora ◽

Subhajit Roychowdhury ◽

Luminita Harnagea ◽

Kumar Saurabh ◽

...

Keyword(s):

Phase Transitions ◽

First Principles ◽

Topological Crystalline Insulator

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Glide-symmetric topological crystalline insulator phase in a nonprimitive lattice

Physical Review B ◽

10.1103/physrevb.102.195202 ◽

2020 ◽

Vol 102 (19) ◽

Cited By ~ 1

Author(s):

Heejae Kim ◽

Shuichi Murakami

Keyword(s):

Topological Crystalline Insulator

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Systematic Investigation of the Coupling between One-Dimensional Edge States of a Topological Crystalline Insulator

Physical Review Letters ◽

10.1103/physrevlett.126.236402 ◽

2021 ◽

Vol 126 (23) ◽

Author(s):

Johannes Jung ◽

Artem Odobesko ◽

Robin Boshuis ◽

Andrzej Szczerbakow ◽

Tomasz Story ◽

...

Keyword(s):

Systematic Investigation ◽

Edge States ◽

One Dimensional ◽

Topological Crystalline Insulator

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Pure spin photocurrent in non-centrosymmetric crystals: bulk spin photovoltaic effect

Nature Communications ◽

10.1038/s41467-021-24541-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Haowei Xu ◽

Hua Wang ◽

Jian Zhou ◽

Ju Li

Keyword(s):

Mirror Symmetry ◽

Photovoltaic Effect ◽

Transition Metal Dichalcogenides ◽

Spin Current ◽

Pure Spin ◽

Light Illumination ◽

Metal Dichalcogenides ◽

Critical Components ◽

Topological Crystalline Insulator

AbstractSpin current generators are critical components for spintronics-based information processing. In this work, we theoretically and computationally investigate the bulk spin photovoltaic (BSPV) effect for creating DC spin current under light illumination. The only requirement for BSPV is inversion symmetry breaking, thus it applies to a broad range of materials and can be readily integrated with existing semiconductor technologies. The BSPV effect is a cousin of the bulk photovoltaic (BPV) effect, whereby a DC charge current is generated under light. Thanks to the different selection rules on spin and charge currents, a pure spin current can be realized if the system possesses mirror symmetry or inversion-mirror symmetry. The mechanism of BSPV and the role of the electronic relaxation time $$\tau$$ τ are also elucidated. We apply our theory to several distinct materials, including monolayer transition metal dichalcogenides, anti-ferromagnetic bilayer MnBi2Te4, and the surface of topological crystalline insulator cubic SnTe.

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