@article{0de6d049f74348c2bde571cd82c9ae0b,
title = "Observation of sixfold degenerate fermions in PdS b2 ",
abstract = "Three types of fermions have been extensively studied in topological quantum materials: Dirac, Weyl, and Majorana fermions. Beyond the fundamental fermions in high energy physics, exotic fermions are allowed in condensed matter systems residing in three-, six-or eightfold degenerate band crossings. Here, we use angle-resolved photoemission spectroscopy to directly visualize three-doubly-degenerate bands in PdSb2. The ultrahigh energy resolution we are able to achieve allows for the confirmation of all the sixfold degenerate bands at the R point, in remarkable consistency with first-principles calculations. Moreover, we find that this sixfold degenerate crossing has quadratic dispersion as predicted by theory. Finally, we compare sixfold degenerate fermions with previously confirmed fermions to demonstrate the importance of this work: our study indicates a topological fermion beyond the constraints of high energy physics.",
author = "Xi{\`a}n Y{\'a}ng and Cochran, {Tyler A.} and Ramakanta Chapai and Damien Tristant and Yin, {Jia Xin} and Ilya Belopolski and Zajiā Ch{\'e}ng and Daniel Multer and Zhang, {Songtian S.} and Nana Shumiya and Maksim Litskevich and Yuxiao Jiang and Guoqing Chang and Qi Zhang and Ilya Vekhter and Shelton, {William A.} and Rongying Jin and Xu, {Su Yang} and Hasan, {M. Zahid}",
note = "Funding Information: Work at Princeton University and Princeton-led synchrotron based ARPES measurements are supported by the U.S. Department of Energy under Grant No. DOE/BES DE-FG-02-05ER46200. Work at LSU is supported by the U.S. Department of Energy (DOE) under EPSCoR Grant No. DE-SC0012432 with additional support from the Louisiana Board of Regents. Part of this work was performed using supercomputing resources provided by Louisiana State University and the Center for Computational Innovations (CCI) at Rensselaer Polytechnic Institute. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. DOE, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. The authors thank D. Lu and M. Hashimoto for beamtime support at SSRL Beamline 5-2. The authors thank the MAX IV Laboratory for access to the Bloch Beamline under Proposal No. 20190502. The authors also thank B. Thiagarajan, C. Polley, H. Fedderwitz, and J. Adell for beamtime support at Bloch. T.A.C. acknowledges the support of the NSF Graduate Research Fellowship Program (DGE-1656466). Publisher Copyright: {\textcopyright} 2020 American Physical Society.",
year = "2020",
month = may,
day = "15",
doi = "10.1103/PhysRevB.101.201105",
language = "English (US)",
volume = "101",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "20",
}