Dielectric Loss due to Charged-Defect Acoustic Phonon Emission
Fuente:
arXiv
Salvato in:
| Autori principali: | , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2024
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866915349249654784 |
|---|---|
| author | Turiansky, Mark E. Van de Walle, Chris G. |
| author_facet | Turiansky, Mark E. Van de Walle, Chris G. |
| contents | The coherence times of state-of-the-art superconducting qubits are limited by bulk dielectric loss, yet the microscopic mechanism leading to this loss is unclear. Here we propose that the experimentally observed loss can be attributed to the presence of charged defects that enable the absorption of electromagnetic radiation by the emission of acoustic phonons. Our explicit derivation of the absorption coefficient for this mechanism allows us to derive a loss tangent of $7.2 \times 10^{-9}$ for Al$_2$O$_3$, in good agreement with recent high-precision measurements [A. P. Read et al., Phys. Rev. Appl. 19, 034064 (2023)]. We also find that for temperatures well below ~0.2 K, the loss should be independent of temperature, also in agreement with observations. Our investigations show that the loss per defect depends mainly on properties of the host material, and a high-throughput search suggests that diamond, cubic BN, AlN, and SiC are optimal in this respect. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2402_17291 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Dielectric Loss due to Charged-Defect Acoustic Phonon Emission Turiansky, Mark E. Van de Walle, Chris G. Quantum Physics Materials Science The coherence times of state-of-the-art superconducting qubits are limited by bulk dielectric loss, yet the microscopic mechanism leading to this loss is unclear. Here we propose that the experimentally observed loss can be attributed to the presence of charged defects that enable the absorption of electromagnetic radiation by the emission of acoustic phonons. Our explicit derivation of the absorption coefficient for this mechanism allows us to derive a loss tangent of $7.2 \times 10^{-9}$ for Al$_2$O$_3$, in good agreement with recent high-precision measurements [A. P. Read et al., Phys. Rev. Appl. 19, 034064 (2023)]. We also find that for temperatures well below ~0.2 K, the loss should be independent of temperature, also in agreement with observations. Our investigations show that the loss per defect depends mainly on properties of the host material, and a high-throughput search suggests that diamond, cubic BN, AlN, and SiC are optimal in this respect. |
| title | Dielectric Loss due to Charged-Defect Acoustic Phonon Emission |
| topic | Quantum Physics Materials Science |
| url | https://arxiv.org/abs/2402.17291 |