文献详情
Observation of unconventional chiral fermions with long Fermi arcs in CoSi
文献类型：期刊
通讯作者：Sun, YJ; Qian, T (reprint author), Chinese Acad Sci, Beijing Natl Lab Condensed Matter Phys, Beijing, Peoples R China.; Sun, YJ; Qian, T (reprint author), Chinese Acad Sci, Inst Phys, Beijing, Peoples R China.; Lei, HC (reprint author), Renmin Univ China, Dept Phys, Beijing, Peoples R China.; Lei, HC (reprint author), Renmin Univ China, Beijing Key Lab Optoelect Funct Mat & Micronano D, Beijing, Peoples R China.; Sun, YJ; Qian, T (reprint author), Songshan Lake Mat Lab, Dongguan, Peoples R China.; Sun, YJ;
期刊名称：NATURE影响因子和分区
年：2019
卷：567
期：7749
页码：496-+
ISSN：0028-0836
所属部门：物理学系
摘要：Chirality-the geometric property of objects that do not coincide with their mirror image-is found in nature, for example, in molecules, crystals, galaxies and life forms. In quantum field theory, the chirality of a massless particle is defined by whether the directions of its spin and motion are parallel or antiparallel. Although massless chiral fermions-Weyl fermions-were predicted 90 years ago, their existence as fundamental particles has not been experimentally confirmed. However, their analo ...More
Chirality-the geometric property of objects that do not coincide with their mirror image-is found in nature, for example, in molecules, crystals, galaxies and life forms. In quantum field theory, the chirality of a massless particle is defined by whether the directions of its spin and motion are parallel or antiparallel. Although massless chiral fermions-Weyl fermions-were predicted 90 years ago, their existence as fundamental particles has not been experimentally confirmed. However, their analogues have been observed as quasiparticles in condensed matter systems. In addition to Weyl fermions(1-4), theorists have proposed a number of unconventional (that is, beyond the standard model) chiral fermions in condensed matter systems(5-8), but direct experimental evidence of their existence is still lacking. Here, by using angle-resolved photoemission spectroscopy, we reveal two types of unconventional chiral fermion-spin-1 and charge-2 fermions-at the band-crossing points near the Fermi level in CoSi. The projections of these chiral fermions on the (001) surface are connected by giant Fermi arcs traversing the entire surface Brillouin zone. These chiral fermions are enforced at the centre or corner of the bulk Brillouin zone by the crystal symmetries, making CoSi a system with only one pair of chiral nodes with large separation in momentum space and extremely long surface Fermi arcs, in sharp contrast to Weyl semimetals, which have multiple pairs of Weyl nodes with small separation. Our results confirm the existence of unconventional chiral fermions and provide a platform for exploring the physical properties associated with chiral fermions. ...Hide

DOI：10.1038/s41586-019-1031-8
重要成果类型：重要期刊
百度学术：Observation of unconventional chiral fermions with long Fermi arcs in CoSi
语言：外文
被引频次：31
人气指数：1
浏览次数：1
基金：Ministry of Science and Technology of ChinaMinistry of Science and Technology, China [2016YFA0401000, 2015CB921000, 2016YFA0300600, 2016YFA0300504, 2016YFA0302400, 2018YFA0305700, 2017YFA0302901]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China [11622435, U1832202, 11474340, 11822412, 11574371, 11674369, 11574394, 11774423, 11774399]; Chinese Academy of SciencesChinese Academy of Sciences [QYZDB-SSW-SLH043, XDB07000000, XDB28000000]; Science Challenge Project [TZ2016004]; K. C. Wong Education Foundation [GJTD-2018-01]; Beijing Natural Science FoundationBeijing Natural Science Foundation [Z180008]; Beijing Municipal Science and Technology CommissionBeijing Municipal Science & Technology Commission [Z171100002017018, Z181100004218005, Z181100004218001]; CAS Pioneer Hundred Talents Program; National Postdoctoral Program for Innovative Talents [BX20170012]
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