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Dissipation induced by phonon elastic scattering in crystals

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ABSTRACT

We demonstrate that the phonon elastic scattering leads to a dominant dissipation in crystals at low temperature. The two-level systems (TLSs) should be responsible for the elastic scattering, whereas the dissipation induced by static-point defects (SPDs) can not be neglected. One purpose of this work is to show how the energy splitting distribution of the TLS ensemble affects the dissipation. Besides, this article displays the proportion of phonon-TLS elastic scattering to total phonon dissipation. The coupling coefficient of phonon-SPD scattering and the constant P0 of the TLS distribution are important that we estimate their magnitudes in this paper. Our results is useful to understand the phonon dissipation mechanism, and give some clues to improve the performance of mechanical resonators, apply the desired defects, or reveal the atom configuration in lattice structure of disordered crystals.

No MeSH data available.


The phonon-PSD coupling coefficient  as a function of the lower bound νi and the range Δν = νf − νi. The unit of  is 10−17 MHz−3, while the units of νi and Δν are both GHz. The color indicates the magnitude of . There is an unallowed region of the νi − Δν plane, otherwise the coefficient  enters the negative region.
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f5: The phonon-PSD coupling coefficient as a function of the lower bound νi and the range Δν = νf − νi. The unit of is 10−17 MHz−3, while the units of νi and Δν are both GHz. The color indicates the magnitude of . There is an unallowed region of the νi − Δν plane, otherwise the coefficient enters the negative region.

Mentions: The above analysis reveals that quality factor at a given temperature is determined by the distribution of energy splitting of TLSs. Apart from the TLS scattering which is responsible for the temperature dependence, the static-point defects also make a contribution to the phonon elastic scattering. The coupling strength of this kind scattering can be determined at fixed lower bound νi and range Δν = νf − νi, according to formula (13) and the parameters given above, as shown in Fig. 5.


Dissipation induced by phonon elastic scattering in crystals
The phonon-PSD coupling coefficient  as a function of the lower bound νi and the range Δν = νf − νi. The unit of  is 10−17 MHz−3, while the units of νi and Δν are both GHz. The color indicates the magnitude of . There is an unallowed region of the νi − Δν plane, otherwise the coefficient  enters the negative region.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036349&req=5

f5: The phonon-PSD coupling coefficient as a function of the lower bound νi and the range Δν = νf − νi. The unit of is 10−17 MHz−3, while the units of νi and Δν are both GHz. The color indicates the magnitude of . There is an unallowed region of the νi − Δν plane, otherwise the coefficient enters the negative region.
Mentions: The above analysis reveals that quality factor at a given temperature is determined by the distribution of energy splitting of TLSs. Apart from the TLS scattering which is responsible for the temperature dependence, the static-point defects also make a contribution to the phonon elastic scattering. The coupling strength of this kind scattering can be determined at fixed lower bound νi and range Δν = νf − νi, according to formula (13) and the parameters given above, as shown in Fig. 5.

View Article: PubMed Central - PubMed

ABSTRACT

We demonstrate that the phonon elastic scattering leads to a dominant dissipation in crystals at low temperature. The two-level systems (TLSs) should be responsible for the elastic scattering, whereas the dissipation induced by static-point defects (SPDs) can not be neglected. One purpose of this work is to show how the energy splitting distribution of the TLS ensemble affects the dissipation. Besides, this article displays the proportion of phonon-TLS elastic scattering to total phonon dissipation. The coupling coefficient of phonon-SPD scattering and the constant P0 of the TLS distribution are important that we estimate their magnitudes in this paper. Our results is useful to understand the phonon dissipation mechanism, and give some clues to improve the performance of mechanical resonators, apply the desired defects, or reveal the atom configuration in lattice structure of disordered crystals.

No MeSH data available.