One-dimensional weak antilocalization due to the berry phase in HgTe wires.
We study the weak antilocalization (WAL) effect in the magnetoresistance of narrow HgTe wires fabricated in quantum wells with normal and inverted band ordering. Measurements at different gate voltages indicate that the WAL is only weakly affected by Rashba spin-orbit splitting and persists when the Rashba splitting is about zero. The WAL amplitude in wires with normal band ordering is an order of magnitude smaller than for wires with an inverted band structure. These observations are attributed to the Dirac-like dispersion of the energy bands in HgTe quantum wells. From the magnetic-field and temperature dependencies we extract the dephasing lengths and band Berry phases. The weaker WAL for samples with a normal band structure can be explained by a nonuniversal Berry phase which always exceeds π, the characteristic value for gapless Dirac fermions.
Faculty of Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Mühlbauer
Faculty of Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Budewitz
Faculty of Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Büttner
Faculty of Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Tkachov
Faculty of Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Hankiewicz
Faculty of Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Brüne
Faculty of Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Buhmann
Faculty of Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
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Molenkamp