Reststrahlen spectra of HgTe and CdxHg1-xTe

Baars, J.; Sorger, F.

doi:10.1016/0038-1098(72)90211-6

Cited by 206 publications

(61 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…1). The fitting parameters, given in Table, are reasonably comparable, in the sense of virtual crystal approximation with literature data for HgTe and its ternary alloys [4][5][6][7][8][9][10][11][12][13][14][15].…”

Section: Resultssupporting

confidence: 73%

See 1 more Smart Citation

Investigation of Phonons in HgCdMnTe Using Far-Infrared Reflectivity

Dudziak¹,

Bożym²,

Pruchnik³

et al. 1993

Acta Phys. Pol. A

View full text Add to dashboard Cite

show abstract

Section: Resultssupporting

confidence: 73%

“…This additional band was observed in HgTe [4,5] and in other Hg compounds and Hg-rich mixed crystals, i.e. [6][7][8][9][10][11][12]. We performed a standard Kramers-Kronig analysis which yields the dielectric function ε(ω) and mode frequencies without presupposing any mode1 for response function.…”

Section: Resultsmentioning

confidence: 99%

Investigation of Phonons in HgCdMnTe Using Far-Infrared Reflectivity

Dudziak¹,

Bożym²,

Pruchnik³

et al. 1993

Acta Phys. Pol. A

View full text Add to dashboard Cite

show abstract

“…Here, C tb is the geometric capacitance C tb ¼ ε HgTe ε 0 A=d HgTe between top and bottom surface, with ε HgTe ≈ 21, the dielectric constant of HgTe [25], d HgTe is the thickness of the HgTe film, A is the gated TI area, and ε 0 the dielectric constant of vacuum. Therefore, the measured capacitance reflects primarily the top surface's DOS, D t .…”

mentioning

confidence: 99%

Probing Quantum Capacitance in a 3D Topological Insulator

et al. 2016

View full text Add to dashboard Cite

We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magnetocapacitance oscillations probe-in contrast to magnetotransportprimarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions of the Fermi energy. DOI: 10.1103/PhysRevLett.116.166802 Three-dimensional topological insulators (3D TI) represent a new class of materials with insulating bulk and conducting two-dimensional surface states [1][2][3][4]. The properties of these surface states are of particular interest as they have a spin degenerate, linear Dirac-like dispersion with spins locked to their electrons' k vectors [4,5]. Strained HgTe, examined here, constitutes a 3D TI with high electron mobilities allowing the observation of Landau quantization and quantum Hall steps down to low magnetic fields [6,7]. While unstrained HgTe is a zero gap semiconductor with inverted band structure [8,9], the degenerate Γ8 states split and a gap opens at the Fermi energy E F if strained. This system is a strong topological insulator [10], explored by transport [6,7,11], angleresolved photoemission spectroscopy [12], photoconductivity, and magneto-optical experiments [13][14][15][16]; also, the proximity effect has been investigated [17]. Since these two-dimensional electron states (2DES) have high electron mobilities of several 10 5 cm 2 =V s, pronounced Shubnikov-de Haas (SdH) oscillations of the resistivity and quantized Hall plateaus commence in quantizing magnetic fields [6,7,11], stemming from both top and bottom 2DES. The oscillations stem from Landau quantization which strongly modifies the density of states (DOS). Capacitance spectroscopy allows us to directly probe the thermodynamic DOS dn=dμ (n ¼ carrier density, μ ¼ electrochemical potential), denoted as D, of a 3D TI. The total capacitance measured between a metallic top gate and a 2DES depends, besides the geometric capacitance, on the quantum capacitance e 2 D, connected in series and reflecting the finite density of states D of the 2DES [18][19][20][21][22]; e is the elementary charge. Below, the quantum capacitance of the top surface is denoted as e 2 D t , the one of the bottom layer by e 2 D b . We show that capacitance measures, in contrast to transport, the properties of a single Dirac cone in a 3D TI.The experiments are carried out on strained 80 nm thick HgTe films, grown by molecular beam epitaxy on CdTe (013). For details, see [16]. The Dirac surface electrons have high electron mobilities of order 4 × 10 5 cm 2 =V s. The cross section of the structure is sketched in Fig. 1(a). For transport and capacitance measurements, carried out on one and the same device, the films were patterned into Hall bars with metallic top gates. Several devices from the same wafer have been studied. The measurement...

show abstract

“…Infrared spectroscopy also delivers an information concerning real crystalline microstructure and interior interactions. J.Baars and F.Sorger [1] interpreted the phonon spectra of Hg 1-x Cd x Te considering two-mode behavior. In Ref.…”

mentioning

confidence: 99%

Additional phonon modes related to intrinsic defects in CdHgTe

Polit¹,

Sheregii

Cebulski

et al. 2009

Phys. Status Solidi (c)

View full text Add to dashboard Cite

The optical reflectivity measurements data are reported. They were obtained by means of synchrotron (DAFNE‐LIGHT in LNF, Italy) as the radiation source as well as mercury lamp, in far infrared region for the 9 sample of Hg1‐xCdxTe (x = 0.06‐0.7) in the temperature interval 20 K‐293 K. The imaginary part of dielectric function obtained by means of Kramers‐Kroning transformation were analyzed in the Lorentzian‐approximation of dielectric function, using the model of deformed tetrahedra. Beside eight canonical phonon modes observed earlier by Kozyrev et al., we observed several additional lines in the region below 120 cm–1. Our analysis is based on the experimental data obtained for the samples of n ‐ and p ‐type and prepared by different manufacture technologies. The temperature dependence of the frequency of vibration modes in the region 90 cm–1–118 cm–1 is also presented and discussed. This analysis has shown that two kinds of lines are observed in this region: the lines of the first type are generated by the electron transitions while the lines of the second one are generated by oscillations in defect‐bearing tetrahedra. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

Reststrahlen spectra of HgTe and CdxHg1-xTe

Cited by 206 publications

References 3 publications

Investigation of Phonons in HgCdMnTe Using Far-Infrared Reflectivity

Investigation of Phonons in HgCdMnTe Using Far-Infrared Reflectivity

Probing Quantum Capacitance in a 3D Topological Insulator

Additional phonon modes related to intrinsic defects in CdHgTe

Contact Info

Product

Resources

About