| Autor: |
M v Schickfus, M. Bazrafshan, G Fickenscher, Achim Fleischmann, Christian Enss |
| Rok vydání: |
2007 |
| Předmět: |
|
| Zdroj: |
Journal of Physics: Conference Series. 92:012135 |
| ISSN: |
1742-6596 |
| Popis: |
A few years ago surprising magnetic field effects were found in non- magnetic glasses at low temperatures (≈ 10 mK). It has since been established that this effect can be attributed to the tunnelling motion of particles carrying nuclear quadrupole moments. The magnetic field effect saturates when the nuclear Zeeman energy becomes larger than the quadrupole splitting. For glycerol this saturation field is around 60 mT. Recently we have observed an additional magnetic field effect which saturates at about 10 times smaller field. This novel phenomenon was studied systematically with 2-pulse dielectric polarization echoes on a series of glycerol samples with different degrees of deuteration. These experiments clearly demonstrate that it originates from the interaction between magnetic dipole moments, giving rise to an energy splitting of approximately 30 kHz. The impact of the nuclear dipoles becomes visible in a quantum beating at zero field and a magnetic field dependence of the echo amplitude. Numerical calculations were performed and compared to the experimental results, shedding light on the microscopic nature of tunnelling systems in glasses. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
