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Non-ohmic variable-range hopping transport in one-dimensional conductors.
1Department of Physics, University of California San Diego, La Jolla, 92093, USA.
Physical Review Letters
|October 26, 2005
Summary
We theoretically investigate how electric fields affect resistivity in disordered one-dimensional systems. Increasing electric fields reduce resistance by overcoming high-resistance breaks in the hopping network.
Area of Science:
- Condensed Matter Physics
- Disordered Systems
- Quantum Transport
Background:
- Understanding electron transport in disordered materials is crucial for device applications.
- Variable-range hopping describes conductivity in certain disordered systems at low temperatures.
Purpose of the Study:
- To theoretically investigate the impact of a finite electric field on the resistivity of a disordered one-dimensional system.
- To analyze the behavior of electron transport in the variable-range hopping regime under an applied electric field.
Main Methods:
- Theoretical investigation using a model for disordered one-dimensional systems.
- Analysis of electron transport within the variable-range hopping regime.
- Examination of the role of localized states and hopping networks.
Main Results:
- At low electric fields, transport is hindered by high-resistance breaks due to fluctuations in localized states.
- As the field increases, these breaks become less resistive.
- In strong fields, breaks are overcome, driving the electron distribution far from equilibrium, leading to specific resistance-field dependencies (exponential drop, logarithmic, inverse square-root).
Conclusions:
- The electric field significantly modifies the hopping transport in disordered 1D systems.
- The interplay between field strength, localized states, and hopping network determines the system's resistivity.
- The observed resistance-field dependencies provide insights into charge transport mechanisms in disordered materials.