Optical properties of Bi<sub>2</sub>Se<sub>3</sub>: from bulk to ultrathin films

Eddrief, M.; Vidal, Franck; Gallas, Bruno

doi:10.1088/0022-3727/49/50/505304

Cited by 46 publications

(57 citation statements)

References 38 publications

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“…These higher band gaps are also consistent with those (1.0 eV and 1.6 eV) estimated from fitting the dielectric functions of bulk Bi 2 Se 3 at 300 K as reported in Ref. 17, although the spin-orbit splitting could not be resolved.…”

supporting

confidence: 91%

“…This seems surprisingly small given the well know high values for the dielectric constant of Bi 2 Se 3 , which has been shown to be of order 30 even up to photon energies as high as 2 eV. 17 However such a value would be consistent with the idea that there is be a significant excitonic contribution to these higher band transitions which influences the band edge absorption.…”

mentioning

confidence: 72%

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Ultrahigh magnetic field spectroscopy reveals the band structure of the three-dimensional topological insulator Bi2Se3

et al. 2017

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We have investigated the band structure at the Γ point of the three-dimensional (3D) topological insulator Bi2Se3 using magneto-spectroscopy over a wide range of energies (0.55 − 2.2 eV) and in ultrahigh magnetic fields up to 150 T. At such high energies (E > 0.6 eV) the parabolic approximation for the massive Dirac fermions breaks down and the Landau level dispersion becomes nonlinear. At even higher energies around 0.99 and 1.6 eV, new additional strong absorptions are observed with a temperature and magnetic-field dependence which suggest that they originate from higher band gaps. Spin orbit splittings for the further lying conduction and valence bands are found to be 0.196 and 0.264 eV.Topological insulators, which have a finite insulating bandgap in the bulk form, but which can become gapless at the surface, have been intensively investigated as a new class of quantum matter.

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confidence: 91%

mentioning

confidence: 72%

Ultrahigh magnetic field spectroscopy reveals the band structure of the three-dimensional topological insulator Bi2Se3

et al. 2017

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“…In the effective surface model, the bulk band contributions to the momentum matrix elements in ıı (ω) are not included. However, this does not change the qualitative behavior of the effects shown in this paper, since the calculated ıı (ω)s are qualitatively similar to experiment [62]. Therefore we argue that all the higher energy MOKE features disccused in this paper would still be seen in experiments, but at higher optical frequencies.…”

supporting

confidence: 57%

“…ε o is the vacuum permittivity. For Bi 2 Se 3 , (ω) is given by Lorentz oscillator fits to experiment [62], which in the low energy regime (0 − 30 meV) is essentially a constant. In the effective surface model, the bulk band contributions to the momentum matrix elements in ıı (ω) are not included.…”

mentioning

confidence: 99%

High figure of merit magneto-optics from interfacial skyrmions on topological insulators

Bhowmick

Lake

2018

Phys. Rev. B

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In the Kerr rotation geometry, magneto optic memory devices typically suffer from low figure-of-merit (FOM) and long write times. We show that skyrmions formed at the interface of a thin-film multiferroic and a topological insulator can give rise to high FOM magneto optic Kerr effects (MOKEs). Huge differential MOKE can arise in parts of the phase diagram. Resonance like features in the MOKE spectra arising from the induced low energy TI bandgap, the multiferroic-film thickness, and the high energy Drude like behavior are resolved and explained. The Fermi level dependence of the MOKE signatures is distinct for the different magnetic textures. This has broad implications for magnetic texture characterization, electro-optic modulators and isolators and high density magnetic optic memory. PACS numbers: Magneto-optic (MO) phenomenon such as Kerr and Faraday rotations, Voigt effect, magneto-plasma reflections and cyclotron resonances arise from broken time reversal symmetry. Some MO effects also arise from the electronic structure's topology, and hence are used to study quantum hall effects[1], Kerr rotations in topological insulators (TIs)[2, 3], magnetoelectric optical effects[4, 5], magneto-chiral effects[6], and skyrmions and their Hall effects[7-9].arXiv:1805.02799v1 [cond-mat.mes-hall]

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“…Data collection and stepper motors positioning were performed by home-written software in LabVIEW ® (National Instruments). We have used very low power for the pump (532 nm laser -1 mW) and probe beam (488 nm laser diode -0.2 mW) to measuring bare Bi 2 Se 3 crystal, which is opaque for the two pump and probe beams [23]. Figure 2 shows the experimental results (amplitude and phase) obtained by scanning the surface around the heat source point on the bare substrate.…”

Section: The Setupmentioning

confidence: 99%

Straightforward measurement of anisotropic thermal properties of a Bi₂Se₃single crystal

Fournier

Marangolo

Eddrief

et al. 2018

J. Phys.: Condens. Matter

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We demonstrate here a simple measurement protocol which allows the thermal properties of anisotropic crystalline materials to be determined. This protocol is validated by the measurement of Bi2Se3, a layered material consisting of covalently bonded sheets with weak van-der-Waals bonds between each layer, which has highly anisotropic thermal properties. Thermoreflectance microscopy measurements were carried out on a single-crystal Bi2Se3 sample, firstly on the bare sample and then after capping wih a 100 nm thick gold layer. Whereas on the bare sample lateral heat diffusion is dominated by the in-plane thermal diffusivity, on the metal-capped substrate heat diffusion perpendicular to the sample surface dominates. Using a simple theoretical model, we show how this double measurement protocol allows the anisotropic thermal conductivity coefficients of bulk Bi2Se3 to be evaluated.

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Optical properties of Bi₂Se₃: from bulk to ultrathin films

Cited by 46 publications

References 38 publications

Ultrahigh magnetic field spectroscopy reveals the band structure of the three-dimensional topological insulator Bi2Se3

Ultrahigh magnetic field spectroscopy reveals the band structure of the three-dimensional topological insulator Bi2Se3

High figure of merit magneto-optics from interfacial skyrmions on topological insulators

Straightforward measurement of anisotropic thermal properties of a Bi₂Se₃single crystal

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Optical properties of Bi2Se3: from bulk to ultrathin films

Cited by 46 publications

References 38 publications

Ultrahigh magnetic field spectroscopy reveals the band structure of the three-dimensional topological insulator Bi2Se3

Ultrahigh magnetic field spectroscopy reveals the band structure of the three-dimensional topological insulator Bi2Se3

High figure of merit magneto-optics from interfacial skyrmions on topological insulators

Straightforward measurement of anisotropic thermal properties of a Bi2Se3single crystal

Contact Info

Product

Resources

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Optical properties of Bi₂Se₃: from bulk to ultrathin films

Straightforward measurement of anisotropic thermal properties of a Bi₂Se₃single crystal