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Эта публикация цитируется в 1 научной статье (всего в 1 статье)
Quantum Hall effect
Magnetocapacitance studies of two-dimensional electron systems with long-range potential fluctuations
M. O. Dorokhova, S. I. Dorozhkin Institute of Solid State Physics, Russian Academy of Sciences, 142432 Chernogolovka, Moscow Region, Russian Federation
Аннотация:
We report on magnetocapacitance study of the
quantum Hall effect (QHE) states. Capacitance minima width
was found to be independent of magnetic field and to be the same
for even, odd and fractional QHE states when measured as a
function of the average electron density. This result indicates
that the width of capacitance minima in the samples investigated
are governed by long-range carrier density fluctuations.
At low temperatures, the amplitudes of the minima decrease
linearly with the temperature increase. All our experimental
results for the integer QHE states are quantitatively explained
by introducing unbroadened magnetic levels and dispersion of
the electron density along the sample. The energy gaps at even
filling factors obtained from fitting the experimental data are
found to be close to the known cyclotron gaps. At odd fillings
$\nu=1$, $3$ and $5$, the energy gaps appear to be enhanced in
comparison with the Zeeman splitting, with the enhancement
decreasing with filling factor.
The capacitance minima are argued to originate from the
motion of incompressible regions along a sample caused by the
gate voltage variation. We derive the condition for the appearance
and motion of such regions for the case of gated samples
with long-range fluctuations of density of charged donors.
The appearance of narrow magnetocapacitance peaks when
a dc current is passed through the sample is reported. We
hypothesize that these peaks are due to the current percolation
along incompressible regions.
Образец цитирования:
M. O. Dorokhova, S. I. Dorozhkin, “Magnetocapacitance studies of two-dimensional electron systems with long-range potential fluctuations”, УФН, 171, приложение к № 10 (2001), 39–44; Phys. Usp., 44:10 suppl. (2001), s39–s44
Образцы ссылок на эту страницу:
https://www.mathnet.ru/rus/ufn5626 https://www.mathnet.ru/rus/ufn/v171/i13/p39
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Страница аннотации: | 97 | PDF полного текста: | 42 |
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