Quantum well resonance

Hunt N. E. J., Schubert E. F., Logan R. A., Zydzik G. J. Enhanced spectral power density and reduced linewidth at 1.3 pm in an InGaAsP quantum well resonant cavity light-emitting diode Appl. Phys. Lett. 61, 2287 (1992). 

The ability to create and observe coherent dynamics in heterostructures offers the intriguing possibility to control the dynamics of the charge carriers. Recent experiments have shown that control in such systems is indeed possible. For example, phase-locked laser pulses can be used to coherently amplify or suppress THz radiation in a coupled quantum well [5]. The direction of a photocurrent can be controlled by exciting a structure with a laser field and its second harmonic, and then varying the phase difference between the two fields [8,9]. Phase-locked pulses tuned to excitonic resonances allow population control and coherent destruction of heavy hole wave packets [10]. Complex filters can be designed to enhance specific characteristics of the THz emission [11,12]. These experiments are impressive demonstrations of the ability to control the microscopic and macroscopic dynamics of solid-state systems. 

Cao, J.R., Kuang, W., Choi, S.-J., Lee, P.-T., O Brien, J.D., Dapkus, P.D., 2003, Threshold dependence on the spectral alignment between the quantum-well gain peak and the cavity resonance in InGaAsP photonic crystal lasers, Appl. Phys. Lett. 83(20) 4107-4109. 

Fig. 13. Absorption between confined energy levels in a quantum well infrared photodetector (QWIP). The energy difference (E —E ) between the confined energy levels in a quantum well may be designed such that it is resonant with ir radiation. The band gap, E is much greater, therefore direct band...

M. Heiblum, M.V. Fischetti, W.P. Dumke, D.J. Frank, I.M. Anderson, C.M. Knoedler, L. Osterling, Electron interference effects in quantum wells Observation of bound and resonant states, Phys. Rev. Lett. 58 (1987) 816. 

Figure 6 A scheme of the three possible resonances in OOTF. i) Global resonance (A). Very weak electron-vibration interaction is expected ii) Localized resonances or traps (B).Usually the LEPS experiments are not detecting electrons trapped in these resonances and they appear as a reduction in the transmission probability, iii) Quantum well structure (C). Here the electron is localized in one dimension, while it is delocalized in the other two dimensions. There is a significant electron-vibration coupling.

It leads to an intense electric dipole spin resonance even if the mean value of the coupling vanishes. It can be measured with the electron spin resonance technique even in Si-based quantum wells, where the SO coupling is very weak. 

Electrically detected magnetic resonance (EDMR) is conceptually similar to ODMR, i.e. the magnetic resonance is observed through spin-dependent electrical rather than optical properties of a sample. Virtually all of the EDMR in GaN-based materials reported to date has bear performed on LEDs and so the device type will serve as a basis for the organisation of this section. Three basic device types have been studied m-i-n-n+ diodes, double heterostructures (DHs) and single quantum wells (SQWs). Some details on these structures can be found elsewhere in this volume [35] and in the original work. 

Chen C.Y., Yeh D.M., Lu Y.C., Yang C.C. Dependence of resonant coupling between surface plasmons and an InGaN quantum well on metallic structure Appl. Phys. Lett. 89 203113. 

More convenient approaches for the elimination of undesired coherences are possible in the case of frequency-selective irradiation schemes. If the spins that are involved in zero-quantum coherences resonate in well-separated spectral regions, the spins can be manipulated separately by selective (or semiselective) pulses (Vincent et al., 1992,1993). For example, a selective 90°(7) pulse transforms the antiphase combination (lyS — I Sy), which corresponds to zero-quantum coherence in the tilted frame, into (I S -t- lySy), whereas (—I S - lySy) is obtained if a 90° (7) pulse is used instead. Hence, a two-step phase cycle eliminates the antiphase terms... 

An equivalent circuit of resonant-tunneling nanostructures taking into account spin-polarized transport of charge carriers is proposed. It is based on the approximation of I-V characteristics and represents spin shifted energy levels in the quantum well. 

Keywords Terahertz Detector Resonant Photoeonduetion Double Quantum Well. 

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