Soft phonons and ultralow lattice thermal conductivity in the Dirac semimetal Cd_{3}As_{2}
Recently, Cd_{3}As_{2} has attracted intensive research interest as an archetypical Dirac semimetal, hosting three-dimensional linear-dispersive electronic bands near the Fermi level. Previous studies have shown that single-crystalline Cd_{3}As_{2} has an anomalously low lattice thermal conductivity...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2019-11-01
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| Series: | Physical Review Research |
| Online Access: | http://doi.org/10.1103/PhysRevResearch.1.033101 |
| _version_ | 1797211664571957248 |
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| author | Shengying Yue Hamid T. Chorsi Manik Goyal Timo Schumann Runqing Yang Tashi Xu Bowen Deng Susanne Stemmer Jon A. Schuller Bolin Liao |
| author_facet | Shengying Yue Hamid T. Chorsi Manik Goyal Timo Schumann Runqing Yang Tashi Xu Bowen Deng Susanne Stemmer Jon A. Schuller Bolin Liao |
| author_sort | Shengying Yue |
| collection | DOAJ |
| description | Recently, Cd_{3}As_{2} has attracted intensive research interest as an archetypical Dirac semimetal, hosting three-dimensional linear-dispersive electronic bands near the Fermi level. Previous studies have shown that single-crystalline Cd_{3}As_{2} has an anomalously low lattice thermal conductivity, ranging from 0.3 to 0.7 W/mK at 300 K, which has been attributed to point defects. In this work, we combine first-principles lattice dynamics calculations and temperature-dependent high-resolution Raman spectroscopy of high-quality single-crystal thin films grown by molecular-beam epitaxy to reveal the existence of a group of soft optical phonon modes at the Brillouin-zone center of Cd_{3}As_{2}. These soft phonon modes significantly increase the scattering phase space of heat-carrying acoustic phonons and are the origin of the low lattice thermal conductivity of Cd_{3}As_{2}. Furthermore, we show that the interplay between the phonon-phonon Umklapp scattering rates and the soft optical phonon frequency explains the unusual nonmonotonic temperature dependence of the lattice thermal conductivity of Cd_{3}As_{2}. Our results further suggest that the soft phonon modes are potentially induced by a Kohn anomaly associated with the Dirac nodes, in analogy to similar, nonetheless weaker, effects in graphene and Weyl semimetals. |
| first_indexed | 2024-04-24T10:30:05Z |
| format | Article |
| id | doaj.art-4ac7bd8ac32a46cdb1d28e1d31a14a77 |
| institution | Directory Open Access Journal |
| issn | 2643-1564 |
| language | English |
| last_indexed | 2024-04-24T10:30:05Z |
| publishDate | 2019-11-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Research |
| spelling | doaj.art-4ac7bd8ac32a46cdb1d28e1d31a14a772024-04-12T16:46:54ZengAmerican Physical SocietyPhysical Review Research2643-15642019-11-011303310110.1103/PhysRevResearch.1.033101Soft phonons and ultralow lattice thermal conductivity in the Dirac semimetal Cd_{3}As_{2}Shengying YueHamid T. ChorsiManik GoyalTimo SchumannRunqing YangTashi XuBowen DengSusanne StemmerJon A. SchullerBolin LiaoRecently, Cd_{3}As_{2} has attracted intensive research interest as an archetypical Dirac semimetal, hosting three-dimensional linear-dispersive electronic bands near the Fermi level. Previous studies have shown that single-crystalline Cd_{3}As_{2} has an anomalously low lattice thermal conductivity, ranging from 0.3 to 0.7 W/mK at 300 K, which has been attributed to point defects. In this work, we combine first-principles lattice dynamics calculations and temperature-dependent high-resolution Raman spectroscopy of high-quality single-crystal thin films grown by molecular-beam epitaxy to reveal the existence of a group of soft optical phonon modes at the Brillouin-zone center of Cd_{3}As_{2}. These soft phonon modes significantly increase the scattering phase space of heat-carrying acoustic phonons and are the origin of the low lattice thermal conductivity of Cd_{3}As_{2}. Furthermore, we show that the interplay between the phonon-phonon Umklapp scattering rates and the soft optical phonon frequency explains the unusual nonmonotonic temperature dependence of the lattice thermal conductivity of Cd_{3}As_{2}. Our results further suggest that the soft phonon modes are potentially induced by a Kohn anomaly associated with the Dirac nodes, in analogy to similar, nonetheless weaker, effects in graphene and Weyl semimetals.http://doi.org/10.1103/PhysRevResearch.1.033101 |
| spellingShingle | Shengying Yue Hamid T. Chorsi Manik Goyal Timo Schumann Runqing Yang Tashi Xu Bowen Deng Susanne Stemmer Jon A. Schuller Bolin Liao Soft phonons and ultralow lattice thermal conductivity in the Dirac semimetal Cd_{3}As_{2} Physical Review Research |
| title | Soft phonons and ultralow lattice thermal conductivity in the Dirac semimetal Cd_{3}As_{2} |
| title_full | Soft phonons and ultralow lattice thermal conductivity in the Dirac semimetal Cd_{3}As_{2} |
| title_fullStr | Soft phonons and ultralow lattice thermal conductivity in the Dirac semimetal Cd_{3}As_{2} |
| title_full_unstemmed | Soft phonons and ultralow lattice thermal conductivity in the Dirac semimetal Cd_{3}As_{2} |
| title_short | Soft phonons and ultralow lattice thermal conductivity in the Dirac semimetal Cd_{3}As_{2} |
| title_sort | soft phonons and ultralow lattice thermal conductivity in the dirac semimetal cd 3 as 2 |
| url | http://doi.org/10.1103/PhysRevResearch.1.033101 |
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