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ABSTRACT: Optical phenomena in GaAs/AlGaAs quantum well nanostructures doped with acceptors were studied in the mid-IR spectral range.
Equilibrium abso rption spectra were measured in a wide temperature range. Modulation of absorption in the presence of a strong
electric field was studied. Absorption spectra revealed features that can be attributed to the resonance states of the acceptors.
Bulletin of the Russian Academy of Sciences Physics 04/2012; 74(1):82-85.
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ABSTRACT: We report the study of the helicity driven photocurrents in graphene excited
by mid-infrared light of a CO$_2$-laser. Illuminating an unbiased monolayer
sheet of graphene with circularly polarized radiation generates -- under
oblique incidence -- an electric current perpendicular to the plane of
incidence, whose sign is reversed by switching the radiation helicity. We show
that the current is caused by the interplay of the circular $ac$ Hall effect
and the circular photogalvanic effect. Studying the frequency dependence of the
current in graphene layers grown on the SiC substrate we observe that the
current exhibits a resonance at frequencies matching the longitudinal optical
phonon in SiC.
05/2011;
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Semiconductors 01/2011; 45(11):1474-1478. · 0.63 Impact Factor
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B. Wittmann, S. N. Danilov,
V. V. Bel'kov,
S. A. Tarasenko,
E. G. Novik,
H. Buhmann,
C. Brüne,
L. W. Molenkamp,
Z. D. Kvon,
N. N. Mikhailov,
S. A. Dvoretsky,
N. Q. Vinh,
A. F. G. van der Meer,
B. Murdin,
S. D. Ganichev
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ABSTRACT: We describe the observation of the circular and linear photogalvanic effects in HgTe/CdHgTe quantum wells. The interband absorption of mid-infrared radiation as well as the intrasubband absorption of terahertz (THz) radiation in the QWs structures is shown to cause a dc electric current due to these effects. The photocurrent magnitude and direction varies with the radiation polarization state and crystallographic orientation of the substrate in a simple way that can be understood from a phenomenological theory. The observed dependences of the photocurrent on the radiation wavelength and temperature are discussed.
02/2010;
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JETP Letters 01/2010; 91(1):35-37. · 1.35 Impact Factor
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JETP Letters 01/2010; 91(1):35-37. · 1.35 Impact Factor
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D A Firsov,
L E Vorobjev,
V A Shalygin,
A N Sofronov,
V Yu Panevin,
M A Vasil'eva,
M Ya Vinnichenko,
P Thumrongsilapa, S N Danilov,
A E Zhukov,
A I Yakimov,
A V Dvurechenskii
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ABSTRACT: Optical absorption is studied in p-doped GaAs/AlGaAs quantum wells at lattice temperatures 4.2–300 K. Features in the absorption spectrum are associated to hole transitions from ground impurity level to resonant impurity states and subbands. Absorption modulation related to hole redistribution between impurity and subband states is studied. Spectra of intraband absorption are studied in Ge/Si quantum dots in equilibrium and under interband optical excitation. Filling the excited states with nonequilibrium holes leads to arising the additional peak in absorption spectrum related to hole transitions from the excited state.
Journal of Physics Conference Series 11/2009; 193(1):012059.
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H. Diehl,
V. A. Shalygin,
L. E. Golub,
S. A. Tarasenko, S. N. Danilov,
V. V. Bel'kov,
E. G. Novik,
H. Buhmann,
C. Brüne,
E. L. Ivchenko,
S. D. Ganichev
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ABSTRACT: We report on the observation of nonlinear magneto-gyrotropic photogalvanic effect in HgTe/HgCdTe quantum wells. The interband absorption of mid-infrared radiation as well as the intrasubband absorption of terahertz radiation in the heterostructures is shown to cause a dc electric current in the presence of an in-plane magnetic field. A cubic in magnetic field component of the photocurrent is observed in quantum wells with the inverted band structure only. The experimental data are discussed in terms of both the phenomenological theory and microscopic models. Comment: 10 pages, 9 figures
05/2009;
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S. N. Danilov,
B. Wittmann,
P. Olbrich,
W. Eder,
W. Prettl,
L. E. Golub,
E. V. Beregulin,
Z. D. Kvon,
N. N. Mikhailov,
S. A. Dvoretsky,
V. A. Shalygin,
N. Q. Vinh,
A. F. G. van der Meer,
B. Murdin,
S. D. Ganichev
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ABSTRACT: We report a fast, room temperature detection scheme for the polarization ellipticity of laser radiation, with a bandwidth that stretches from the infrared to the terahertz range. The device consists of two elements, one in front of the other, that detect the polarization ellipticity and the azimuthal angle of the ellipse. The elements, respectively, utilize the circular photogalvanic effect in a narrow gap semiconductor and the linear photogalvanic effect in a bulk piezoelectric semiconductor. For the former we characterized both a HgTe quantum well and bulk Te, and for the latter, bulk GaAs. In contrast with optical methods we propose is an easy to handle all-electric approach, which is demonstrated by applying a large number of different lasers from low power, continuous wave systems to high power, pulsed sources.
Journal of Applied Physics 02/2009; · 2.17 Impact Factor
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ABSTRACT: The resonant circular photogalvanic effect is observed in wurtzite (0001)-oriented GaN low-dimensional structures excited by infrared radiation. The current is induced by angular momentum transfer of photons to the photoexcited electrons at resonant inter-subband optical transitions in a GaN/AlGaN heterojunction. The signal reverses upon the reversal of the radiation helicity or, at fixed helicity, when the propagation direction of the photons is reversed. Making use of the tunability of the free-electron laser FELIX we demonstrate that the current direction changes by sweeping the photon energy through the intersubband resonance condition, in agreement with theoretical considerations.
09/2008;
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ABSTRACT: Two types of room-temperature detectors of terahertz laser radiation have been developed which allow, in an all-electric manner, the determination of the plane of polarization of linearly polarized radiation and the Stokes parameters of elliptically polarized radiation, respectively. The operation of the detectors is based on photogalvanic effects in semiconductor quantum well structures of low symmetry. The photogalvanic effects have nanosecond time constants at room temperature, making a high time resolution of the polarization detectors possible.
Journal of Applied Physics 07/2008; · 2.17 Impact Factor
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W. Weber,
L. E. Golub, S. N. Danilov,
J. Karch,
C. Reitmaier,
B. Wittmann,
V. V. Bel'kov,
E. L. Ivchenko,
Z. D. Kvon,
N. Q. Vinh,
A. F. G. van der Meer,
B. Murdin,
S. D. Ganichev
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ABSTRACT: Photogalvanic effects are observed and investigated in wurtzite (0001)-oriented GaN/AlGaN low-dimensional structures excited by terahertz radiation. The structures are shown to represent linear quantum ratchets. Experimental and theoretical analysis exhibits that the observed photocurrents are related to the lack of an inversion center in the GaN-based heterojunctions. Comment: technical reasons
04/2008;
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D. A. Firsov,
L. E. Vorobjev,
V. A. Shalygin,
V. Yu. Panevin,
A. N. Sofronov,
S. D. Ganichev, S. N. Danilov,
A. V. Andrianov,
A. O. Zakhar’in,
A. E. Zhukov,
V. S. Mikhrin,
A. P. Vasil’ev
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ABSTRACT: Spontaneous emission of terahertz radiation from structures with GaAs/AlGaAs quantum wells in a longitudinal magnetic field
has been studied. It is shown that some bands in the emission spectrum can be related to radiative electron transitions between
resonant and localized impurity states, as well as to the transitions with participation of subband states. The temperature
dependence of the equilibrium intraband absorption of terahertz radiation and its modulation in a longitudinal electric field
in GaAs/AlGaAs quantum wells has been investigated.
Bulletin of the Russian Academy of Sciences Physics 01/2008; 72(2):246-248.
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ABSTRACT: We report on the observation of the terahertz radiation induced circular (CPGE) and linear (LPGE) photogalvanic effects in
HgTe quantum wells. The current response is well described by the phenomenological theory of CPGE and LPGE.
12/2007: pages 7-9;
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S.D. Ganichev, S.N. Danilov,
C. Gerl,
D.A. Firsov,
L.E. Vorobjev,
V.A. Shalygin,
V.Yu. Panevin,
A.N. Sofronov,
A.A. Andrianov,
A.O. Zakhar'in,
A.E. Zhukov,
V.S. Mikhrin,
A.P. Vasil'ev
[show abstract]
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ABSTRACT: Spontaneous emission of terahertz radiation, equilibrium intraband terahertz light absorption and its temperature dependence are studied in GaAs/AlGaAs quantum well (QW) structures subjected to a lateral electric field. The emission spectrum consists of several lines we attribute to electron transitions between resonant and localized impurity states and to the electron transitions with participation of subband states.
Infrared and Millimeter Waves, 2007 and the 2007 15th International Conference on Terahertz Electronics. IRMMW-THz. Joint 32nd International Conference on; 10/2007
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B. Wittmann,
R. Ravash,
H. Diehl, S.N. Danilov,
Z.D. Kvon,
S.A. Tarasenko,
E.L. Ivchenko,
N.N. Mikhailov,
S.A. Dvoretsky,
W. Prettl,
S.D. Ganichev
[show abstract]
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ABSTRACT: We report on the observation of the terahertz radiation induced circular (CPGE) and linear (LPGE) photogalvanic effects in HgTe quantum wells. The current response is well described by the phenomenological theory of CPGE and LPGE.
Infrared and Millimeter Waves, 2007 and the 2007 15th International Conference on Terahertz Electronics. IRMMW-THz. Joint 32nd International Conference on; 10/2007
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ABSTRACT: We report on a room temperature detector of infrared/THz laser radiation allowing to measure the radiation polarization state with picosecond time resolution. The ellipticity of radiation is analyzed applying three photoelectric phenomena: circular photogalvanic effect, linear photogalvanic effect, and photon drag effect. Each of these effects is monitored by different detector units stacked together in one detector.
Infrared and Millimeter Waves, 2007 and the 2007 15th International Conference on Terahertz Electronics. IRMMW-THz. Joint 32nd International Conference on; 10/2007
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H Diehl,
V A Shalygin,
V V Bel'kov,
Ch Hoffmann, S N Danilov,
T Herrle,
S A Tarasenko,
D Schuh,
Ch Gerl,
W Wegscheider,
W Prettl,
S D Ganichev
[show abstract]
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ABSTRACT: The circular photogalvanic effect and the circular photon drag effect are observed and investigated in detail in (110)-grown quantum well structures. The experimental data are well described by phenomenological theory and microscopic models of both effects are developed being in agreement with experimental data.
New Journal of Physics 09/2007; 9(9):349. · 4.18 Impact Factor
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W. Weber,
S. Seidl, S. N. Danilov,
W. Prettl,
V. V. Bel'kov,
L. E. Golub,
E. L. Ivchenko,
Z. D. Kvon,
Hyun-Ick Cho,
Jung-Hee Lee,
S. D. Ganichev
[show abstract]
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ABSTRACT: The magneto-gyrotropic photogalvanic and spin-galvanic effects are observed in (0001)-oriented GaN/AlGaN heterojunctions excited by terahertz radiation. We show that free-carrier absorption of linearly or circularly polarized terahertz radiation in low-dimensional structures causes an electric photocurrent in the presence of an in-plane magnetic field. Microscopic mechanisms of these photocurrents based on spin-related phenomena are discussed. Properties of the magneto-gyrotropic and spin-galvanic effects specific for hexagonal heterostructures are analyzed. Comment: Accepted for publication in Solid State Communications
09/2007;
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[show abstract]
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ABSTRACT: A room temperature detector of terahertz laser radiation ellipticity has been developed based on the simultaneous measurements of three different photoelectric phenomena: circular photogalvanic effect, linear photogalvanic effect, and photon drag effect. Each of these effects, which have subnanosecond time constants, is monitored by different detector units stacked together in one detector.
Applied Physics Letters 08/2007; 91(9):091101-091101-3. · 3.84 Impact Factor
