Abstract
We have studied quantum wires using the Green’s function technique within density-functional theory, calculating electronic structures and conductances for different wire lengths, temperatures, and bias voltages. For short wires, i.e., quantum point contacts, the zero-bias conductance shows as a function of the gate voltage and at a finite temperature a plateau at around 0.7G0. (G0=2e2/h is the quantum conductance.) The behavior, which is caused in our mean-field model by spontaneous spin polarization in the constriction, is reminiscent of the so-called 0.7 anomaly observed in experiments. In our model the temperature and the wire length affect the conductance–gate-voltage curves similarly as in experiments.
Original language | English |
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Article number | 233308 |
Pages (from-to) | 1-4 |
Number of pages | 4 |
Journal | Physical Review B |
Volume | 70 |
Issue number | 23 |
DOIs | |
Publication status | Published - 17 Dec 2004 |
MoE publication type | A1 Journal article-refereed |
Keywords
- 0.7-anomaly
- quantum wire
- spin polarization