Journal article
Linear and nonlinear optical responses in the chiral multifold semimetal RhSi
NPJ QUANTUM MATERIALS, v 5(1), 96
18 Dec 2020
Abstract
Chiral topological semimetals are materials that break both inversion and mirror symmetries. They host interesting phenomena such as the quantized circular photogalvanic effect (CPGE) and the chiral magnetic effect. In this work, we report a comprehensive theoretical and experimental analysis of the linear and nonlinear optical responses of the chiral topological semimetal RhSi, which is known to host multifold fermions. We show that the characteristic features of the optical conductivity, which display two distinct quasi-linear regimes above and below 0.4 eV, can be linked to excitations of different kinds of multifold fermions. The characteristic features of the CPGE, which displays a sign change at 0.4 eV and a large non-quantized response peak of around 160 mu A/V-2 at 0.7 eV, are explained by assuming that the chemical potential crosses a flat hole band at the Brillouin zone center. Our theory predicts that, in order to observe a quantized CPGE in RhSi, it is necessary to increase the chemical potential as well as the quasiparticle lifetime. More broadly, our methodology, especially the development of the broadband terahertz emission spectroscopy, could be widely applied to study photogalvanic effects in noncentrosymmetric materials and in topological insulators in a contact-less way and accelerate the technological development of efficient infrared detectors based on topological semimetals.
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Details
- Title
- Linear and nonlinear optical responses in the chiral multifold semimetal RhSi
- Publication Details
- NPJ QUANTUM MATERIALS, v 5(1), 96
- Publisher
- NATURE RESEARCH; BERLIN
- Grant note
- We thank G. Chang and Z. Fang for helpful discussions. Z.N. and L.W. are supported by Army Research Office under Grant W911NF1910342. J.W.F.V. is supported by a seed grant from NSF MRSEC at Penn under the Grant DMR-1720530. B.X. and C.B. were supported by the Schweizerische Nationalfonds (SNF) by Grant No. 200020-172611. M.-A.S.-M acknowledges support from the European Union's Horizon 2020 research and innovation program under the Marie-Sklodowska-Curie grant agreement No. 754303 and the GreQuE Cofund program. A.G.G. is supported by the ANR under the grant ANR-18-CE30-0001-01 (TOPODRIVE) and the European Union Horizon 2020 research and innovation program under grant agreement No. 829044 (SCHINES). F.d.J. acknowledges funding from the Spanish MCI/AEI through grant No. PGC2018-101988-B-C21. Y.Z. is currently supported by the DOE Office of Basic Energy Sciences under Award desc0018945 to Liang Fu. Y.Z., K.M., and C.F. acknowledge financial support from the European Research Council (ERC) Advanced Grant No. 742068 TOP-MAT and Deutsche Forschungsgemeinschaft (Project-ID 258499086 and FE 63330-1). This research was supported in part by the National Science Foundation under Grant No. NSF PHY11-25915. The DFT calculations were carried out on the Draco cluster of MPCDF, Max Planck society.
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Drexel University
- Web of Science ID
- WOS:000600110000001
- Scopus ID
- 2-s2.0-85097746606
- Other Identifier
- 991021860778104721
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- Collaboration types
- Domestic collaboration
- International collaboration
- Web of Science research areas
- Materials Science, Multidisciplinary
- Physics, Applied
- Physics, Condensed Matter
- Quantum Science & Technology