Low frequency charge-density wave dynamics

The low frequency dynamics of the charge-density waves in NbSe$\sb3$ and TaS$\sb3$ were investigated using low frequency conductance fluctuations. Simultaneous measurements of the fluctuations in the voltage and the differential resistance revealed a theory of threshold voltage fluctuations can only partially describe some of the fluctuations in the I-V curve. Noise measurements performed with an ac drive current characterized the fluctuations and showed that other parameters, in addition to the threshold, must be fluctuating to fully account for the fluctuations. In mesoscopic samples, the observation of discrete switching in the voltage allowed estimates of the dynamical coherence length ranging from \rm{\approx}100μ m up to the entire sample length of \rm{\approx}1000μ m. Experiments to determine if the low frequency dynamics are equilibrium or nonequilibrium processes showed that the dynamics involve a combination of equilibrium and nonequilibrium dynamics. The equilibrium dynamics can be described by a rough free energy landscape with extreme sensitivity of the local details of the landscape to changes in the temperature or current. The nonequilibrium dynamics were directly related to the drive current.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Marley, Arley Cleveland

Contributors dc:contributor

• Weissman, Michael B.

• Physics, Condensed Matter

Statement dc:rights

• Copyright 1996 Marley, Arley Cleveland

Language dc:language

eng

Identifier

AAI9624428
(UMI)AAI9624428

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/22715