Low-temperature dipolar echoes in amorphous dielectrics: Significance of relaxation and decoherence free two-level systems
| Autor: | Christian Enss, Christian Schötz, M. von Schickfus, M. Bazrafshan, John M. Leveritt, Alexander L. Burin, Paul Fassl, Achim Fleischmann, G. Ruyters |
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| Rok vydání: | 2013 |
| Předmět: |
Quantum decoherence
Phonon FOS: Physical sciences General Physics and Astronomy 02 engineering and technology Dielectric Condensed Matter - Soft Condensed Matter 01 natural sciences Power law 0103 physical sciences 010306 general physics Condensed Matter - Statistical Mechanics Computer Science::Cryptography and Security Physics Statistical Mechanics (cond-mat.stat-mech) Condensed matter physics Relaxation (NMR) Disordered Systems and Neural Networks (cond-mat.dis-nn) Condensed Matter - Disordered Systems and Neural Networks 021001 nanoscience & nanotechnology 3. Good health Amorphous solid Amplitude Orders of magnitude (time) Soft Condensed Matter (cond-mat.soft) 0210 nano-technology |
| Zdroj: | EPL (Europhysics Letters). 104:57006 |
| ISSN: | 1286-4854 0295-5075 |
| DOI: | 10.1209/0295-5075/104/57006 |
| Popis: | The nature of dielectric echoes in amorphous solids at low temperatures is investigated. It is shown that at long delay times the echo amplitude is determined by a small subset of two level systems (TLS) having negligible relaxation and decoherence because of their weak coupling to phonons. The echo decay can then be described approximately by power law time dependencies with different powers at times longer and shorter than the typical TLS relaxation time. The theory is applied to recent measurements of two and three pulse dipolar echo in borosilicate glass BK7 and provides a perfect data fit in the broad time and temperature ranges under the assumption that there exist two TLS relaxation mechanisms due to TLS-phonons and TLS-TLS interaction. This interpretation is consistent with the previous experimental and theoretical investigations. Further experiments verifying the theory predictions are suggested. Comment: 10 pages, 8 figures |
| Databáze: | OpenAIRE |
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