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Spin-incoherent transport in quantum wires
W K Hew1, K J Thomas, M Pepper
1Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
Physical Review Letters
|September 4, 2008
Summary
Conductance plateaus in quantum wires are affected by magnetic fields. Weakly confined wires show a unique e{2}/h plateau that changes with magnetic field strength, suggesting spin-incoherent transport.
Area of Science:
- Condensed matter physics
- Quantum transport phenomena
Background:
- Quantum wires exhibit quantized conductance plateaus at specific carrier densities.
- Weak confinement in one-dimensional systems can lead to unique transport behaviors.
Purpose of the Study:
- To investigate the effect of in-plane magnetic fields on conductance plateaus in weakly confined quantum wires.
- To understand the underlying transport mechanisms, particularly spin-related effects.
Main Methods:
- Experimental measurement of electrical conductance in a quantum wire.
- Systematic variation of carrier density and in-plane magnetic field strength.
Main Results:
- A conductance plateau at e{2}/h appears with decreasing carrier density in zero magnetic field.
- This e{2}/h plateau initially weakens and then strengthens with increasing in-plane magnetic field (B_{ parallel}).
- The 2e{2}/h plateau is suppressed and then restored by the magnetic field.
Conclusions:
- The observed magnetic field dependence of conductance plateaus is consistent with spin-incoherent transport.
- Spin dynamics play a crucial role in one-dimensional quantum transport under magnetic fields.
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