| Conductivity in strong parallel magnetic fields up to 14 Tesla was measured in a Si-MOSFET with a slot in the upper gate which allows to vary the electron density in different parts of the sample. Conductivity across the slot was measured as a function of a DC current of opposite directions. It is shown that in the case of large difference of the electron density and in strong magnetic fields, the sample resistance depends on the direction of DC current. The anisotropy of conductivity is assumed to be caused by the necessity of spin-flip when electrons move between areas with different spin polarization. |
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