Evolution of the spin-split quantum Hall states with magnetic field tilt in the InAs-based double quantum wells

Yakunin, M. V.; Visser, A. de; Galistu, G.; Подгорных, С. М.; Sadofyev, Yu. G.; Shelushinina, N. G.; Harus, G. I.

doi:10.1088/1742-6596/150/2/022100

Cited by 2 publications

(1 citation statement)

References 8 publications

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“…E F passes through this gap in the vicinity of three points where the levels cross. Existence of groups of closely spaced levels was observed to cause a similar distortion of the QH plateau in the shape of a dip (e.g., in a traditional DQW 23,24 ). A possible cause for appearance of such a dip on the QH plateau may be connected with an interplay between current carrying strips at the sample edges, 25 and close positions of the neighboring levels may promote the effect.…”

Section: Peculiarities In the Qh Range Of Fieldsmentioning

confidence: 94%

Magnetotransport in double quantum well with inverted energy spectrum: HgTe/CdHgTe

Yakunin¹,

Суслов²,

Popov³

et al. 2016

Phys. Rev. B

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We present the first experimental study of the double-quantum-well (DQW) system made of 2D layers with inverted energy band spectrum: HgTe. The magnetotransport reveals a considerably larger overlap of the conduction and valence subbands than in known HgTe single quantum wells (QW), which may be regulated here by an applied gate voltage Vg. This large overlap manifests itself in a much higher critical field Bc separating the range above it with a plain behavior of the Hall magnetoresistance ρxy(B), where the quantum peculiarities shift linearly with Vg, and the range below with a complicated behavior. In the latter case specific structures in ρxy(B) are formed like a double-N -shaped ρxy(B), reentrant sign-alternating quantum Hall effect with transitions into a zero-filling-factor state etc., which are clearly manifested here due to better magnetic quantization at high fields, as compared to the features seen earlier in a single HgTe QW. The coexisting electrons and holes were found in the whole investigated range of positive and negative Vg as revealed (i) from fits to the low-field N -shaped ρxy(B), (ii) from the Fourier analysis of oscillations in ρxx(B) and (iii) from a specific behavior of ρxy(B) at high positive Vg. A peculiar feature here is that the found electron density n remains almost constant in the whole range of investigated Vg while the hole density p drops down from the value a factor of 6 larger than n at extreme negative Vg to almost zero at extreme positive Vg passing through the charge neutrality point. We show that this difference between n and p stems from an order of magnitude larger density of states for holes in the lateral valence subband maxima than for electrons in the conduction subband minimum. We analyze our observations on the basis of a calculated picture of magnetic levels in a DQW and suggest that their specificity is due to (i) a nonmonotonic course of the valence subband magnetic levels and an oscillating behavior of the valence subband top versus field due to lateral maxima in the energy spectrum, (ii) a reduced gap between the lowest electron and the highest hole magnetic levels where the electron-and hole-type localized states are superposed, and (iii) a possible formation of the interlayer electron-hole excitons.

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Section: Peculiarities In the Qh Range Of Fieldsmentioning

confidence: 94%