Ladder structure in the time-domain response of Landau levels to a shock electromagnetic pulse

The light absorption A and reflection R coefficients for a three-level system in a quantum well (QW) in a strong magnetic field H, directed perpendicularly to the QW's plane, have been calculated. The energy levels correspond to the ground state and to magnetopolaron energy levelshω 1(2) with the inverse lifetimes γ r1(2) and γ 1(2) . The inverse radiative lifetime of an EHP γ rξ (K ⊥ ) = 0 only under condition K ⊥ ≤ ω ξ n/c, wherehω ξ is the EHP energy. It has been shown that γ rξ (K ⊥ ) is proportional to H. The values γra(K ⊥ ) and γ rb (K ⊥ ) for an excitation consisting of a hole and a usual magnetopolaron have been calculated. The index a(b) designates a magnetopolaron upper (lower) term. In the resonance at Hres = mecωLO/|e| γ res ra = γ res rb = γ res rξ 0 /2, where the index ξ0 corresponds to the EHP with ne = n h = 1. γra and γ rb are strongly dependent on H − Hres. A numerical estimate for GaAs is: γ res rξ 0 = γ0 = 5.35 · 10 −5 eV. The dependencies A(H) and R(H) for various values of ω l in the magnetophonon resonance vicinity have been obtained. The existence of "combined"and "weak" polarons has been predicted. The resonant value Hres for the combined polaron case depends on a QW's depth and width.

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“…(92) is Π → c, v, p; k ey , k hy , l e , l h . ‡ The corresponding formula from Ref [25]. coincides with Eq.…”

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confidence: 58%

“…wherẽ (2) . (25) Note that the value in the square root in Eq. (24) is, generally speaking, a complex one.…”

Section: Electric Fields Out Of Qwmentioning

confidence: 99%

A manifestation of the magnetopolaron effect in reflection and absorption of light by a three-level system in a quantum well

et al. 2002

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“…Therefore the results obtained above are justified for any number of the excited energy levels in a QW (see for instance [10,11,12,13,14]), but not only in the case of the only energy level, where the expression Eq. (15) is applicable.…”

Section: Electric Fields On the Right And Left Side Of A Qw Irramentioning

confidence: 85%

“…In [1,10,11] the strongly asymmetrical pulse has been used with a sharp front, for which γ l2 → ∞ and the second term in Eq. (5) vanishes, as well as the second term in the square brackets in Eq.…”

Section: Electric Fields On the Right And Left Side Of A Qw Irramentioning

confidence: 99%

“…In the perfect QWs the radiative lifetime broadening γ r may be comparable to and even exceed the contributions of other relaxation mechanisms. This new physical situation requires the adequate theoretical description where the upper orders of the electron-EMF (electro magnetic field) are taken into account [1,2,3,4,5,6,7,8,9,10,11,12,13,14]. γ r has been calculated for an excitonic energy level in a QW at H = 0 in [2], in a strong magnetic field in [11,12], for a magnetopolaron in a QW in [12], respectively.…”

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confidence: 99%

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Change in the shape of a symmetric light pulse passing through a quantum well

et al. 2000

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The theory of a response of a two-energy-level system, irradiated by symmetrical light pulses, has been developed.(Suchlike electronic system approximates under the definite conditions a single ideal quantum well (QW) in a strong magnetic field H, directed perpendicularly to the QW's plane, or in magnetic field absence.) The ground state system energy level is the first energy level, the excitation discrete energy level with the energyhω0 (for instance, an excitonic energy level at H = 0 or any energy level in a strong magnetic field) is the second energy level. It is supposed that one can neglect a light-lattice interaction and influence of all other energy levels. The general formulae for the time-dependence of non-dimensional reflection R(t), absorption A(t) and transmission T (t) of a symmetrical light pulse have been obtained. It has been shown that singularities of three types exist on the dependencies R(t), A(t), T (t). In the first type of singularity t0 R(t) = R(t) = 0 and the total reflection is realized. In the case γr >> γ (γr is the radiative lifetime broadening, γ is the non-radiative lifetime broadening) and under the resonant condition ω l = ω0 the strong alterations of the value and profile of the transmitted pulse can happen. In the case of the long pulse (γr >> γ l , γ l is the lifetime broadening of the exciting pulse) it is almost totally reflected. In the case of the intermediate pulse (γr ≃ γ l ) reflection, absorption and transmission are comparable in values, the transmitted pulse profile distinguishes strongly from the exciting pulse profile: the transmitted pulse has two maxima due to the total reflection point t0, when transmission is absent. The oscillating time dependence of R(t), A(t), T (t) on the detuning frequency ∆ω = ω l − ω0 takes place. The oscillations are better observable when ∆ω ≃ γ l . The positions of the total absorption, reflection and transparency singularities are examined when the frequency ω l is detuned.

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Magneto-optical effects in quantum wells irradiated with light pulses

et al. 2000

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The method of detection and investigation of the magnetopolaron effect in the semiconductor quantum wells (QW) in a strong magnetic field, based on pulse light irradiation and measuring the reflected and transmitted pulses, has been proposed. It has been shown that a beating amplitude on the frequencies, corresponding to the magnetopolaron energy level splitting, depends strongly on the exciting pulse width. The existence of the time points of the total reflection and total transparency has been predicted. The high orders of the perturbation theory on electron-electromagnetic field interaction have been taken into account.

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Ladder structure in the time-domain response of Landau levels to a shock electromagnetic pulse

Cited by 14 publications

References 5 publications

A manifestation of the magnetopolaron effect in reflection and absorption of light by a three-level system in a quantum well

A manifestation of the magnetopolaron effect in reflection and absorption of light by a three-level system in a quantum well

Change in the shape of a symmetric light pulse passing through a quantum well

Magneto-optical effects in quantum wells irradiated with light pulses

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