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L. P. Rokhinson

Publications and source records attributed to L. P. Rokhinson.

21 records · Page 2Linked to original sources

Magnetoresistance of composite fermions at ν=1/2

We have studied temperature dependence of both diagonal and Hall resistivity in the vicinity of $ν=1/2$. Magnetoresistance was found to be positive and almost independent of temperature: temperature enters resistivity as a logarithmic correction. At the same time, no measurable corrections to the Hall resistivity has been found. Neither of these results can be explained within the mean-field theory of composite fermions by an analogy with conventional low-field interaction theory. There is an indication that interactions of composite fermions with fluctuations of the gauge field may reconcile the theory and experiment.

cond-mat.mes-hall↗

Logarithmic temperature dependence of conductivity at half-integer filling factors: Evidence for interaction between composite fermions

We have studied the temperature dependence of diagonal conductivity in high-mobility two-dimensional samples at filling factors $ν=1/2$ and 3/2 at low temperatures. We observe a logarithmic dependence on temperature, from our lowest temperature of 13 mK up to 400 mK. We attribute the logarithmic correction to the effects of interaction between composite fermions, analogous to the Altshuler-Aronov type correction for electrons at zero magnetic field. The paper is accepted for publication in Physical Review B, Rapid Communications.

cond-mat↗

Peak Values of Conductivity in Integer and Fractional Quantum Hall Effect

The diagonal conductivity $σ_{xx}$ was measured in the Corbino geometry in both integer and fractional quantum Hall effect (QHE). We find that peak values of $σ_{xx}$ are approximately equal for transitions in a wide range of integer filling factors $3<ν<16$, as expected in scaling theories of QHE. This fact allows us to compare peak values in the integer and fractional regimes within the framework of the law of corresponding states.

cond-mat↗