Perex
We have proposed an original method of characterizing the electrostatic screening of electron gas by means of a highly sensitive capacitance bridge. Using this method, we measured, at low temperatures (1.2 K - 4 K), the dependence of the density of screening electron states in low-dimensional semiconductor structures on the magnetic field.
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From the shape of the curves obtained at different temperatures we have concluded that in the quantum Hall regime at certain magnetic fields the two-dimensional electron gas is transformed into one-dimensional conducting channels (so-called dragon curves). It is a topological phase transition that is similar to the transition between vortex and non-vortex flux observed in superfluid helium.
J. J. Mareš, A. Siddiki, D. Kindl, P. Hubík, and J. Krištofik
Electrostatic screening and experimental evidence of a topological phase transition in a bulk quantum Hall liquid
New Journal of Physics 11 (2009) 083028 (17pp).
ReferenceJ. J. Mareš, A. Siddiki, D. Kindl, P. Hubík, and J. Krištofik
Electrostatic screening and experimental evidence of a topological phase transition in a bulk quantum Hall liquid
New Journal of Physics 11 (2009) 083028 (17pp).