Quantum coherence in a ferromagnetic metal: Time-dependent conductance fluctuations

[摘要] Quantum coherence of electrons in ferromagnetic metals is difficult to assess experimentally. We report measurements of time-dependent universal conductance fluctuations in ferromagnetic metal (Ni0.8Fe0.2) nanostructures as a function of temperature and magnetic field strength and orientation. We find that the Cooperon contribution to this quantum correction is suppressed, and that domain wall motion can be a source of coherence-enhanced conductance fluctuations. The fluctuations are more strongly temperature dependent than those in normal metals, hinting that an unusual dephasing mechanism may be at work.

[发布日期] 2004-12-01

[关键词] DOMAIN-WALL;1/F NOISE;ANISOTROPIC MAGNETORESISTANCE;WEAK-LOCALIZATION;LOW-TEMPERATURE;MAGNETIC-FIELD;THIN-FILMS;CONDUCTIVITY;INTERFERENCE;PARTICLES