Self-consistent modelling based on local spin-density formalism is employed to calculate the conductance of quantum point contacts at finite temperatures. The total electrostatic potential exhibits spin-dependent splitting, which persists at temperatures up to 0.5 K and gives rise to the anomalies at 0.4 and 0.7 of the conductance quantum (2e~2/h) occurring simultaneously in the absence of external magnetic fields.
展开▼