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Tunneling measurements of the coulomb pseudogap in a two-dimensional electron system in a quantizing magnetic field

E. V. Deviatov·A. A. Shashkin·V. T. Dolgopolov·W. Hansen·M. Holland
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Abstract

We study the Coulomb pseudogap for tunneling into the two-dimensional electron system of high-mobility (Al,Ga)As/GaAs heterojunctions subjected to a quantizing magnetic field at filling factor $ν\leq 1$. Tunnel current-voltage characteristics show that for the double maximum observed in the tunnel resistance at $ν\approx 1$ the pseudogap is linear in energy with a slope that depends on filling factor, magnetic field, and temperature. We give a qualitative account of the filling factor dependence of the pseudogap slope and we confirm the recently reported appearance of another relaxation time for tunneling at $ν\approx 1$. For the tunnel resistance peaks at $ν=1/3$ and 2/3 a completely different behaviour of the current-voltage curves is found and interpreted as manifestation of the fractional gap.

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E. V. Deviatov, A. A. Shashkin, V. T. Dolgopolov, W. Hansen, M. Holland. 1999-12-03. Tunneling measurements of the coulomb pseudogap in a two-dimensional electron system in a quantizing magnetic field. https://doi.org/10.1103/physrevb.61.2939

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