Observation and control of maximal Chern numbers in a chiral topological semimetal

doi:10.1126/science.aaz3480

GSTDTAP > 气候变化

DOI	10.1126/science.aaz3480
	Observation and control of maximal Chern numbers in a chiral topological semimetal
	Niels B. M. Schröter; Samuel Stolz; Kaustuv Manna; Fernando de Juan; Maia G. Vergniory; Jonas A. Krieger; Ding Pei; Thorsten Schmitt; Pavel Dudin; Timur K. Kim; Cephise Cacho; Barry Bradlyn; Horst Borrmann; Marcus Schmidt; Roland Widmer; Vladimir N. Strocov; Claudia Felser
	2020-07-10
发表期刊	Science
出版年	2020
英文摘要	Topologically nontrivial electronic structure can often be characterized by the Chern number, the value of which is related to the magnitude of some of the exotic effects predicted to occur in such systems. Many topological phases discovered so far have a Chern number of 1 or 2, but higher values are also theoretically possible. Schröter et al. predicted that the chiral material palladium gallium (PdGa) would have a Chern number of 4, and they confirmed that prediction using photoemission experiments. Interestingly, the sign of the Chern number was opposite for the two enantiomers of PdGa. Science , this issue p. [179][1] Topological semimetals feature protected nodal band degeneracies characterized by a topological invariant known as the Chern number ( C ). Nodal band crossings with linear dispersion are expected to have at most \|C\|=4, which sets an upper limit to the magnitude of many topological phenomena in these materials. Here, we show that the chiral crystal palladium gallium (PdGa) displays multifold band crossings, which are connected by exactly four surface Fermi arcs, thus proving that they carry the maximal Chern number magnitude of 4. By comparing two enantiomers, we observe a reversal of their Fermi-arc velocities, which demonstrates that the handedness of chiral crystals can be used to control the sign of their Chern numbers. [1]: /lookup/doi/10.1126/science.aaz3480
领域	气候变化 ; 资源环境
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文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/283399
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Niels B. M. Schröter,Samuel Stolz,Kaustuv Manna,et al. Observation and control of maximal Chern numbers in a chiral topological semimetal[J]. Science,2020.
APA	Niels B. M. Schröter.,Samuel Stolz.,Kaustuv Manna.,Fernando de Juan.,Maia G. Vergniory.,...&Claudia Felser.(2020).Observation and control of maximal Chern numbers in a chiral topological semimetal.Science.
MLA	Niels B. M. Schröter,et al."Observation and control of maximal Chern numbers in a chiral topological semimetal".Science (2020).