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Effect of a local perturbation in a fermionic ladder
Sam T Carr1, Boris N Narozhny, Alexander A Nersesyan
1Institut für Theorie der Kondensierten Materie and DFG Center for Functional Nanostructures, Karlsruher Institut für Technologie, 76128 Karlsruhe, Germany.
Physical Review Letters
|April 27, 2011
Summary
We investigated how external potentials affect spin-polarized nanowires. A specific potential gradient can completely block electron transport, offering a new method for sensing potential fields.
Area of Science:
- Condensed Matter Physics
- Nanoscience
- Quantum Transport
Background:
- Understanding electron behavior in nanoscale systems is crucial for developing new electronic devices.
- Spin-polarized transport in nanowires is a key area for spintronics research.
- External potentials can significantly alter quantum transport phenomena.
Purpose of the Study:
- To investigate the impact of local external potentials on the transport properties of parallel spin-polarized nanowires.
- To explore the sensitivity of nanowire conductance to the characteristics of applied potentials.
- To identify potential applications for observed phenomena in sensing technologies.
Main Methods:
- Theoretical modeling of electron transport in a two-nanowire system.
- Analysis of the system's response to local external potentials with varying gradients.
- Calculation of conductance at zero temperature for different potential configurations.
Main Results:
- Transport properties are highly sensitive to the transverse gradient of the external potential.
- An asymmetric potential gradient leads to complete electron reflection and zero conductance at zero temperature.
- A flat potential remains transparent, allowing for unimpeded electron flow.
Conclusions:
- The conductance of spin-polarized nanowires is critically dependent on the gradient of local external potentials.
- Asymmetric potentials can induce a vanishing conductance state, a novel effect.
- This sensitivity can be exploited for the development of highly sensitive local potential field gradient sensors.
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