title: Backscattering of Dirac fermions in HgTe quantum wells with a finite gap.
abstract: The density-dependent mobility of n-type HgTe quantum wells with inverted band ordering has been studied both experimentally and theoretically. While semiconductor heterostructures with a parabolic dispersion exhibit an increase in mobility with carrier density, high-quality HgTe quantum wells exhibit a distinct mobility maximum. We show that this mobility anomaly is due to backscattering of Dirac fermions from random fluctuations of the band gap (Dirac mass). Our findings open new avenues for the study of Dirac fermion transport with finite and random mass, which so far has been hard to access.
authors.affiliation: Fakultät für Physik und Astronomie and Röntgen Center for Complex Material Systems, Universität Würzburg, Am Hubland, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Tkachov
authors.forename: C
authors.initials: C
authors.lastname: Thienel
authors.forename: V
authors.initials: V
authors.lastname: Pinneker
authors.forename: B
authors.initials: B
authors.lastname: Büttner
authors.forename: C
authors.initials: C
authors.lastname: Brüne
authors.forename: H
authors.initials: H
authors.lastname: Buhmann
authors.forename: L W
authors.initials: LW
authors.lastname: Molenkamp
authors.forename: E M
authors.initials: EM
authors.lastname: Hankiewicz