Multi-Welled Tunneling Model for the Magnetic-Field Effect in Ultracold Glasses

Abstract

Puzzling observations of both thermal and dielectric responses in multi-silicate glasses at low temperatures $T$ to static magnetic fields $B$ have been reported in the last decade and call for an extension of the standard two-level systems tunneling model. An explanation is proposed, capable of capturing at the same time the $T$- and $B$-dependence of the specific heat $C_p$ and of the dielectric constant $\epsilon$ in these glasses. This theory points to the existence of anomalous multi-welled tunneling systems in the glasses -- alongside the standard two-level systems -- and indications are given for glasses which should achieve larger electric magnetocapacitive enhancements.

4 pages, 3 figures, submitted for publication (31 October 2008)

References in corpus (5)

• Channel Formation and Intermediate Range Order in Sodium Silicate Melts and Glasses
• Dephasing of Atomic Tunneling by Nuclear Quadrupoles
• Magnetic field effect on the dielectric constant of glasses: Evidence of disorder within tunneling barriers
• The effect of Aharanov-Bohm phase on the magnetic-field dependence of two-pulse echos in glasses at low temperatures
• Paramagnetic tunneling state concept of the low-temperature magnetic anomalies of multicomponent insulating glasses

Cited by in corpus (5)

• Realistic Tunneling States for the Magnetic Effects in Non-Metallic Real Glasses
• Direct Evidence for a Two-component Tunnelling Mechanism in the Multicomponent Glasses at Low Temperatures
• Paramagnetic tunneling systems and their contribution to the polarization echo in glasses (extended)
• Revealing the Intrinsic Magnetism of Non-Magnetic Glasses
• A new Phenomenon: Glass Paramagnetism. Further Experimental and Theoretical Details