Observation of the Intraexciton Autler-Townes Effect in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>GaAs</mml:mi><mml:mo>/</mml:mo><mml:mi>AlGaAs</mml:mi></mml:math>Semiconductor Quantum Wells

Ultrashort terahertz pulses derived from femtosecond table-top sources have become a valuable tool for time-resolved spectroscopy during the last two decades. Until recently, the pulse energies and field strengths of these pulses have been generally too low to allow for the use as pump pulses or the study of nonlinear effects in the terahertz range. In this review article we will describe methods of generation of intense single cycle terahertz pulses with emphasis on optical rectification using the tilted-pulse-front pumping technique. We will also discuss some applications of these intense pulses in the emerging field of nonlinear terahertz spectroscopy.

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“…However, few studies have been reported on the nonlinear terahertz characteristics of semiconductors using high fields [112,15,113].…”

Section: Nonlinear Thz Spectroscopy Of Semiconductorsmentioning

confidence: 99%

Intense ultrashort terahertz pulses: generation and applications

Hoffmann¹,

Fülöp²

2011

J. Phys. D: Appl. Phys.

332

215

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“…The advent of sources of intense terahertz electromagnetic radiation enables the study of semiconductors in a regime where time-dependent perturbation theory fails completely. Exciting new quantum coherent phenomena emerge, including the dynamical Franz-Keldysh effect [6,7], non-linear excitonic effects [8][9][10][11], and highorder sideband generation [12][13][14]. High-order sideband generation is a cousin of high-order harmonic generation from atoms in intense laser fields [15][16][17].…”

mentioning

confidence: 99%

Terahertz Electron-Hole Recollisions inGaAs/AlGaAsQuantum Wells: Robustness to Scattering by Optical Phonons and Thermal Fluctuations

et al. 2013

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Electron-hole recollisions are induced by resonantly injecting excitons with a near-IR laser at frequency fNIR into quantum wells driven by a 10 kV/cm field oscillating at fTHz = 0.57 THz. At T = 12 K, up to 18 sidebands are observed at frequencies f sideband = fNIR + 2nfTHz, with −8 ≤ 2n ≤ 28. Electrons and holes recollide with total kinetic energies up to 57 meV, well above the ELO = 36 meV threshold for longitudinal optical (LO) phonon emission. Sidebands with order up to 2n = 22 persist up to room temperature. A simple model shows that LO phonon scattering suppresses but does not eliminate sidebands associated with kinetic energies above ELO.The interaction of electrons and holes in semiconductors has long been a rich area of study in physics. In most cases, the electron and hole are treated as point particles within the effective mass approximation [1]. In this approximation, the effects of the lattice are parametrized by the dielectric constant of the semiconductor and the effective masses of the electrons and holes. Calculations based on the effective mass approximation successfully predict, for example, the binding energies and the frequencies of internal transitions of impurity-bound electrons and excitons in GaAs [2] and in GaAs/AlGaAs quantum wells [3][4][5]. The effective mass approximation, however, belies the rich complexity of the microscopic physics. In GaAs, for example, ground-state excitons are collective excitations of more than 10 5 atoms in the crystal. The advent of sources of intense terahertz electromagnetic radiation enables the study of semiconductors in a regime where time-dependent perturbation theory fails completely. Exciting new quantum coherent phenomena emerge, including the dynamical Franz-Keldysh effect [6,7], non-linear excitonic effects [8][9][10][11], and highorder sideband generation [12][13][14]. High-order sideband generation is a cousin of high-order harmonic generation from atoms in intense laser fields [15][16][17]. Excitons are created by a near-infrared laser in a semiconductor driven by an intense terahertz field. The terahertz field ionizes the exciton into an electron and a hole that it then pulls apart and smashes back together. Upon recollision, the electron and hole can recombine across the band gap with the acquired kinetic energy carried off by light with frequency above that of the near-IR laser.In this Letter, we report that the electron-hole recollision process-which, in its theoretical descriptions to date has been treated as a purely ballistic process-is surprisingly robust against scattering. We report electronhole recollisions both with kinetic energy well above the threshold for emission of a longitudinal optical (LO) phonon and at room temperature. We model our results by treating the electron-hole pair as a single particle with the appropriate reduced mass subject to dephasing and LO phonon scattering.Two quantum well (QW) samples with 20 QW repetitions were studied. Both samples were grown on semiinsulating GaAs substrates by molecular beam epitax...

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“…As to optical transitions between the dressed states (13) and (14), they can be described by the matrix dipole elementsd where d…”

Section: Model Of Electronic Structurementioning

confidence: 99%

“…Therefore, the system "electron + strong field" is conventionally considered as a composite electron-field object which was called "electron dressed by field" (dressed electron) [1,2]. The field-induced modification of physical properties of dressed electrons was studied in both atomic systems [1][2][3] and various condensed-matter structures, including bulk semiconductors [4][5][6], graphene [7][8][9][10][11], quantum wells [12][13][14][15][16][17], quantum rings [18][19][20][21], quantum dots [22][23][24][25][26][27][28][29][30][31][32], etc. Among these structures, quantum dots (QDs) -semiconductor 3D structures of nanometer scale, which are referred to as "artificial atoms" -seem to be most interesting for optical studies since they are basic elements of modern nanophotonics [33,34].…”

Section: Introductionmentioning

confidence: 99%

Resonance fluorescence from an asymmetric quantum dot dressed by a bichromatic electromagnetic field

2017

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We present the theory of resonance fluorescence from an asymmetric quantum dot driven by a two-component electromagnetic field with two different frequencies, polarizations and amplitudes (bichromatic field) in the regime of strong light-matter coupling. It follows from the elaborated theory that the broken inversion symmetry of the driven quantum system and the bichromatic structure of the driving field result in unexpected features of the resonance fluorescence, including the infinite set of Mollow triplets, the quench of fluorescence peaks induced by the dressing field, and the oscillating behavior of the fluorescence intensity as a function of the dressing field amplitude. These quantum phenomena are of general physical nature and, therefore, can take place in various double-driven quantum systems with broken inversion symmetry.

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Observation of the Intraexciton Autler-Townes Effect inGaAs/AlGaAsSemiconductor Quantum Wells

Cited by 123 publications

References 29 publications

Intense ultrashort terahertz pulses: generation and applications

Intense ultrashort terahertz pulses: generation and applications

Terahertz Electron-Hole Recollisions inGaAs/AlGaAsQuantum Wells: Robustness to Scattering by Optical Phonons and Thermal Fluctuations

Resonance fluorescence from an asymmetric quantum dot dressed by a bichromatic electromagnetic field

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