Abstract-Suppressed Auger scattering and tunable light emission of Landau-quantized massless Kane electrons

D. B. But, M. Mittendorff, C. Consejo, F. Teppe, N. N. Mikhailov, S. A. Dvoretskii, C. Faugeras, S. Winnerl, M. Helm, W. Knap, M. Potemski & M. Orlita

https://www.nature.com/articles/s41566-019-0496-1

The Landau level laser was proposed long ago as a unique source of monochromatic radiation that would be widely tunable in the THz and infrared spectral ranges using a magnetic field. However, despite many efforts, this appealing concept never progressed to the design of a reliable device. This is because of the efficient Auger scattering of Landau-quantized electrons, an intrinsic non-radiative recombination channel that eventually gains over cyclotron emission in all materials studied so far (conventional semiconductors with parabolic bands, but also in graphene with massless electrons). Auger processes are favoured in these systems because the Landau levels (or their subsets) are equally spaced in energy. Here, we show that this scheme does not apply to massless Kane electrons in gapless HgCdTe, where undesirable Auger scattering is strongly suppressed and sizeable cyclotron emission is observed. The gapless HgCdTe thus appears as a material of choice for future Landau level lasers.

Abstract-Terahertz Spectroscopy of Two-Dimensional Semimetal in Three-Layer InAs/GaSb/InAs Quantum Well

S. S. Krishtopenko, S. Ruffenach, F. Gonzalez-Posada, C. Consejo, W. Desrat, B. Jouault, W. Knap, M. A. Fadeev, A. M. Kadykov, V. V. Rumyantsev, S. V. Morozov, G. Boissier, E. Tournié, V. I. Gavrilenko, F. Teppe

https://link.springer.com/article/10.1134%2FS0021364019020085

The features of terahertz photoluminescence and magnetoabsorption in magnetic fields up to 16 T in threelayer InAs/GaSb/InAs quantum wells with a band structure corresponding to a “two-dimensional semimetal” are studied. The comparison of the positions and amplitudes of the photoluminescence lines with the theoretical calculations of oscillator strengths for interband and intraband transitions performed using the eight-band Kane Hamiltonian indicates the existence of a nonradiative recombination channel associated with the overlap of the conduction and valence bands. The energies of interband and intraband Landau level transitions observed in the magnetoabsorption spectra are in good agreement with theoretical calculations, which confirms the predicted band structure.

Abstract-Temperature-dependent terahertz spectroscopy of inverted-band three-layer InAs/GaSb/InAs quantum well

S. S. Krishtopenko, S. Ruffenach, F. Gonzalez-Posada, G. Boissier, M. Marcinkiewicz, M. A. Fadeev, A. M. Kadykov, V. V. Rumyantsev, S. V. Morozov, V. I. Gavrilenko, C. Consejo, W. Desrat, B. Jouault, W. Knap, E. Tournié,  F. Teppe,

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.245419

We report on temperature-dependent terahertz spectroscopy of a three-layer InAs/GaSb/InAs quantum well (QW) with inverted-band structure. The interband optical transitions, measured up to 16 T at different temperatures by Landau-level magnetospectroscopy, demonstrate the inverted-band structure of the QW. The terahertz photoluminescence at different temperatures allows us to directly extract the optical gap in the vicinity of the $\Gamma$ point of the Brillouin zone. Our results experimentally demonstrate that the gap in the three-layer QWs is temperature independent and exceeds by four times the maximum band gap available in the inverted InAs/GaSb bilayers.

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Abstract-Temperature-dependent terahertz spectroscopy of inverted-band three-layer InAs/GaSb/InAs quantum well

S. S. Krishtopenko, S. Ruffenach, F. Gonzalez-Posada, G. Boissier, M. Marcinkiewicz, M. A. Fadeev, A. M. Kadykov, V. V. Rumyantsev, S. V. Morozov, V. I. Gavrilenko, C. Consejo, W. Desrat, B. Jouault, W. Knap, E. Tournié, and F. Teppe

https://journals.aps.org/prb/accepted/95079Oa7D2d1623e752d64e9057de647e3bf908f7

We report on temperature-dependent terahertz spectroscopy of three-layer InAs/GaSb/InAs quantum well (QW) with inverted band structure. The inter-band optical transitions, measured up to 16~T at different temperatures by Landau level magnetospectroscopy, demonstrate the inverted band structure of the QW. The terahertz photoluminescence at different temperatures allows us directly extracting the optical gap in the vicinity of the $\Gamma$ point of the Brillouin zone. Our results experimentally demonstrate that the gap in the three-layer QWs is temperature-independent and exceeds by four times the maximum band gap available in the inverted InAs/GaSb bilayers.

Abstract-Reducing noise equivalent power in InP DHBT terahertz detector by biasing the collector

 N. Dyakonova,  D. Coquillat,   D. But,  C. Consejo, F. Teppe, W. Knap,  L. Varani,  S. Blin,  V. Nodjiadjim,   A. Konczy,

http://ieeexplore.ieee.org/document/7986010/


We present the low frequency noise and the photoresponse in InP double heterojunction bipolar transistor (DHBT) THz detectors. A current responsivity of 0.23 A/W and a noise equivalent power of 4·10−10 W/Hz1/2 have been measured at 1 kHz modulation frequency. The collector bias can substantially reduce the noise equivalent power.