Unifying description of the vibrational anomalies of amorphous materials
The vibrational density of states D(ω) of solids controls their thermal and transport properties. In crystals, the low-frequency modes are extended phonons distributed in frequency according to Debye's law, D(ω)∝ω^{2}. In amorphous solids, phonons are damped, and at low frequency D(ω) comprises...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2022
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| Online Access: | https://hdl.handle.net/10356/160012 |
| _version_ | 1811684307640516608 |
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| author | Mahajan, Shivam Ciamarra, Massimo Pica |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Mahajan, Shivam Ciamarra, Massimo Pica |
| author_sort | Mahajan, Shivam |
| collection | NTU |
| description | The vibrational density of states D(ω) of solids controls their thermal and transport properties. In crystals, the low-frequency modes are extended phonons distributed in frequency according to Debye's law, D(ω)∝ω^{2}. In amorphous solids, phonons are damped, and at low frequency D(ω) comprises extended modes in excess over Debye's prediction, leading to the so-called boson peak in D(ω)/ω^{2} at ω_{bp}, and quasilocalized ones. Here we show that boson peak and phonon attenuation in the Rayleigh scattering regime are related, as suggested by correlated fluctuating elasticity theory, and that amorphous materials can be described as homogeneous isotropic elastic media punctuated by quasilocalized modes acting as elastic heterogeneities. Our numerical results resolve the conflict between theoretical approaches attributing amorphous solids' vibrational anomalies to elastic disorder and localized defects. |
| first_indexed | 2024-10-01T04:26:33Z |
| format | Journal Article |
| id | ntu-10356/160012 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T04:26:33Z |
| publishDate | 2022 |
| record_format | dspace |
| spelling | ntu-10356/1600122023-02-28T20:07:57Z Unifying description of the vibrational anomalies of amorphous materials Mahajan, Shivam Ciamarra, Massimo Pica School of Physical and Mathematical Sciences CNRS@CREATE LTD Science::Physics Amorphous Materials Phonons The vibrational density of states D(ω) of solids controls their thermal and transport properties. In crystals, the low-frequency modes are extended phonons distributed in frequency according to Debye's law, D(ω)∝ω^{2}. In amorphous solids, phonons are damped, and at low frequency D(ω) comprises extended modes in excess over Debye's prediction, leading to the so-called boson peak in D(ω)/ω^{2} at ω_{bp}, and quasilocalized ones. Here we show that boson peak and phonon attenuation in the Rayleigh scattering regime are related, as suggested by correlated fluctuating elasticity theory, and that amorphous materials can be described as homogeneous isotropic elastic media punctuated by quasilocalized modes acting as elastic heterogeneities. Our numerical results resolve the conflict between theoretical approaches attributing amorphous solids' vibrational anomalies to elastic disorder and localized defects. Ministry of Education (MOE) Published version We acknowledge support from the Singapore Ministry of Education through the Singapore Academic Research Fund (Grant No. MOE2019-T1-001-03), and the National Supercomputing Centre Singapore (NSCC) for the computational resources. 2022-07-07T08:18:21Z 2022-07-07T08:18:21Z 2021 Journal Article Mahajan, S. & Ciamarra, M. P. (2021). Unifying description of the vibrational anomalies of amorphous materials. Physical Review Letters, 127(21), 215504-. https://dx.doi.org/10.1103/PhysRevLett.127.215504 0031-9007 https://hdl.handle.net/10356/160012 10.1103/PhysRevLett.127.215504 34860101 2-s2.0-85120001788 21 127 215504 en MOE2019-T1-001-03 Physical Review Letters © 2021 American Physical Society. All rights reserved. This paper was published in Physical Review Letters and is made available with permission of American Physical Society. application/pdf |
| spellingShingle | Science::Physics Amorphous Materials Phonons Mahajan, Shivam Ciamarra, Massimo Pica Unifying description of the vibrational anomalies of amorphous materials |
| title | Unifying description of the vibrational anomalies of amorphous materials |
| title_full | Unifying description of the vibrational anomalies of amorphous materials |
| title_fullStr | Unifying description of the vibrational anomalies of amorphous materials |
| title_full_unstemmed | Unifying description of the vibrational anomalies of amorphous materials |
| title_short | Unifying description of the vibrational anomalies of amorphous materials |
| title_sort | unifying description of the vibrational anomalies of amorphous materials |
| topic | Science::Physics Amorphous Materials Phonons |
| url | https://hdl.handle.net/10356/160012 |
| work_keys_str_mv | AT mahajanshivam unifyingdescriptionofthevibrationalanomaliesofamorphousmaterials AT ciamarramassimopica unifyingdescriptionofthevibrationalanomaliesofamorphousmaterials |