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| VOLUME 98 (2013) | ISSUE 12 | PAGE 947 |
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Metal-insulator transition in a HgTe quantum well under hydrostatic pressure
E. B. Olshanetsky+, Z. D. Kvon+*, Ya. A. Gerasimenko×, V. A. Prudkoglyad×, V. M. Pudalov×°, N. N. Mikhailov+, S. A. Dvoretsky+
+Rzhanov Institute of Semiconductor Physics SB of the RAS, 630090 Novosibirsk, Russia *Novosibirsk State University, 630090 Novosibirsk, Russia ×Lebedev Physical Institute of the RAS, 119991 Moscow, Russia °Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
Abstract
The 2D semimetal in a 20 nm (100) HgTe quantum well is characterized by a comparatively low overlap between the conduction and the valence bands induced by lattice mismatch. In the present paper we report the results of transport measurements in this quantum well under hydrostatic pressure of 14.4 kbar. By applying pressure we have further reduced the band overlap, thereby creating favorable conditions for the formation of the excitonic insulator state. As a result, we observed that the metallic-like temperature dependence of the conductivity at lowering temperature sharply changes to the activated behavior, signalling the onset of an excitonic insulator regime. |