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Dynamics of electron in a surface quantum well

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Chinese Physics B 2009年第6期18卷 2523-2528页

作者：王立飞杨光参 School of Physics and Electronic Information Wenzhou University

This paper studies the quantum dynamics of electrons in a surface quantum well in the time domain with auto- correlation of wave packet. The evolution of the wave packet for different manifold eigenstates with finite and infinite lifetimes is investigated analytically. It is found that the quantum coherence and evolution of the surface electronic wave packet can be controlled by the laser central energy and electric field. The results show that the finite lifetime of excited states expedites the dephasing of the coherent electronic wave packet significantly. The correspondence between classical and quantum mechanica is shown explicitly in the system.

关键词： quantum well electronic wavepacket autocorrelation function

Piezoelectric and deformation potential effects of straindependent luminescence in semiconductor quantum well structures

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Nano Research 2017年第1期10卷 134-144页

作者： Aihua Zhang Mingzeng Peng Morten Willatzen Junyi Zhai Zhong Lin Wang Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences National Center for Nanoscience and Technology (NCNST) Beijing 100083 China Department of Photonics Engineering Technical University of Denmark DK-2800 Kgs. Lyngby Denmark School of Materials Science and Engineering Georgia Institute of Technology Atlanta Georgia 30332-0245 USA

The mechanism of strain-dependent luminescence is important for the rational design of pressure-sensing devices. The interband momentum-matrix element is the key quantity for understanding luminescent phenomena. We analytically solved an infinite quantum well （IQW） model with strain, in the framework of the 6 × 6 k.p Hamiltonian for the valence states, to directly assess the interplay between the spin-orbit coupling and the strain-induced deformation potential for the interband momentum-matrix element. We numerically addressed problems of both the infinite and IQWs with piezoelectric fields to elucidate the effects of the piezoelectric potential and the deformation potential on the straindependent luminescence. The experimentally measured photoluminescence variation as a function of pressure can be qualitatively explained by the theoretical results.

关键词： piezoelectric potential deformation potential luminescence quantum well

Tunable resonant radiation force exerted on semiconductor quantum well nanostructures: Nonlocal effects

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Chinese Physics B 2017年第10期26卷 389-394页

作者：王光辉颜雄硕张金珂 Guangzhou Key Laboratory for Special Fiber Photonic Devices South China Normal University Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and DevicesSouth China Normal University

Resonant radiation force exerted on a semiconductor quantum well nanostructure （QWNS） from intersubband transition of electrons is investigated by taking the nonlocal coupling between the polarizability of electrons and applied optical fields into account for two kinds of polarized states. The numerical results show the spatial nonlocality of optical response can induce the spectral peak position of the exerted force to have a blueshift, which is sensitively dependent on the polarized state and the QWNS width. It is also demonstrated that resonant radiation force is controllable by the polarization and incident directions of applied light waves. This work provides effective methods for controlling optical force and manipulating nano-objects, and observing radiation forces in experiment. This nonlocal interaction mechanism can also be used to probe and predominate internal quantum properties of nanostructures, and to manipulate collective behavior of nano-objects.

关键词： nonlocal effect radiation force quantum well nanostructure

Ultraslow optical solitons in tunnel-coupled double semiconductor quantum well

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Chinese Physics B 2009年第4期18卷 1528-1533页

作者：陈爱喜徐彦秋邓黎周素云 Department of Applied Physics East China Jiaotong University Department of Physics Jiangxi Science and Technology Normal University

This paper investigates the nonlinear evolution of the pulse probe field in an asymmetric coupled-quantum well driven coherently by a pulse probe field and two controlled fields. This study shows that, by choosing appropriate physical parameters, self-modulation can precisely balance group velocity dispersion in the investigated system, leading to the formation of ultraslow optical solitons of the probe field. The proposed scheme may lead to the development of the controlled technique of optical buffers and optical delay lines.

关键词： ultraslow optical soliton quantum well group velocity

Bound polarons in quantum dot quantum well structures

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Chinese Physics B 2009年第5期18卷 1935-1941页

作者：邢雁王志平王旭 Department of Physics Inner Mongolia University

The problem of bound polarons in quantum dot quantum well （QDQW） structures is studied theoretically. The eigenfrequencies of bulk longitudinal optical （LO） and surface optical （SO） modes are derived in the framework of the dielectric continuum approximation. The electron-phonon interaction Hamiltonian for QDQW structures is obtained and the exchange interaction between impurity and LO-phonons is discussed. The binding energy and the trapping energy of the bound polaron in CdS/HgS QDQW structures are calculated. The numerical results reveal that there exist three branches of eigenfrequencies of surface optical vibration in the CdS/HgS QDQW structure. It is also shown that the binding energy and the trapping energy increase as the inner radius of the QDQW structure decreases, with the outer radius fixed, and the trapping energy takes a major part of the binding energy when the inner radius is very small.

关键词： bound polaron quantum dot quantum well

A tunable dual-narrowband band-pass filter using plasma quantum well structure

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Chinese Physics B 2014年第6期23卷 370-374页

作者：戴燚刘少斌王身云孔祥鲲陈忱 College of Electronic and Information Engineering Nanjing University of Aeronautics & Astronautics College of Electronic and Information Egineering Nanjing University of Information Science and Technology

A tunable dual-narrowband pass-band filter is designed. A one-dimensional photonic crystal （1D PC） is comprised of alternate dielectric layer and vacuum layer. Two quantum wells （QWs） as defects can be constructed by sandwiching two plasma slabs symmetrically in the 1D PC, and a dual-narrowband pass-band filter is formed. The conventional finite- difference time-domain （FDTD） method and piecewise linear current density recursive convolution （PLCDRC）-FDTD method are applied to the dielectric and plasma, respectively. The simulation results illustrate that the dual-narrowband frequencies can be tuned by changing the plasma frequency. The pass band interval and the half-power bandwidths （-3-dB band widths） are related to the space interval between two QWs.

关键词： quantum well dual-narrowband pass-band filter plasma

High sensitivity Hall devices with AlSb/InAs quantum well structures

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Chinese Physics B 2013年第5期22卷 453-455页

作者：张杨张雨溦王成艳关敏崔利杰李弋洋王宝强朱战平曾一平 Key Laboratory of Semiconductor Materials Science Chinese Academy of Sciences Material Science Center Institute of SemiconductorsChinese Academy of Sciences

A1Sb/InAs quantum well （QW） structures and InAs films on GaAs （001） substrates were grown by molecular beam epitaxy （MBE）. We investigated the dependence of electron mobility and two-dimensional electron gas （2DEG） concen- tration on the thickness of an InAs Channel. It is found that electron mobility as high as 19050 cm2 · V-1 · s-1 has been achieved for an InAs channel of 22.5 nm. The Hall devices with high sensitivity and good temperature stability were fabricated based on the A1Sb/InAs QW structures. Their sensitivity is markedly superior to Hall devices of InAs films.

关键词： antimonide semiconductors quantum well molecular beam epitaxy

Modelling and optical response of a compressive-strained AlGaN/GaN quantum well laser diode

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Journal of Semiconductors 2020年第6期41卷 29-34页

作者： A.Menani L.Dehimi S.Dehimi F.Pezzimenti Laboratory of Metallic and Semiconducting Materials(LMSM) Department of Electrical EngineeringBiskra UniversityBiskraAlgeria Faculty of Science Elhadj Lakhdar UniversityBatnalAlgeria Research Centre in Industrial Technology(CRTI) AlgiersAlgeria DIIES–Mediterranea University of Reggio Calabria Reggio CalabriaItaly

The effects of the quantum well(QW)width,carrier density,and aluminium(Al)concentration in the barrier layers on the optical characteristics of a gallium nitride(GaN)-based QW laser diode are investigated by means of a careful modelling analysis in a wide range of *** device’s optical gain is calculated by using two different band energy *** first is based on the simple band-to-band model that accounts for carrier transitions between the first levels of the conduction band and valence band,whereas the second assumes the perturbation theory(k.p model)for considering the valence intersubband transitions and the relative absorption losses in the *** results reveal that the optical gain increases with increasing the n-type doping density as well as the Al molar fraction of the AlxGa1–xN layers,which originate the GaN compressivestrained *** particular,a significant optical gain on the order of 5000 cm^-1 is calculated for a QW width of 40A at room *** addition,the laser threshold current density is of few tens of A/cm^2 at low temperatures.

关键词： laser diode quantum well optical gain threshold current temperature

Dielectric confinement on exciton binding energy and nonlinear optical properties in a strained Zn_(1-x_(in))Mg_(x(in))Se/Zn_(1-x(out))Mg_(x(out))Se quantum well

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Journal of Semiconductors 2012年第9期33卷 1-7页

作者： J.Abraham Hudson Mark A.John Peter Department of Physics NPR Arts&Science CollegeNathamDindigul-624401India Department of Physics Government Arts CollegeMelur-625106MaduraiIndia

The band offsets for a Zn1-xin Mgxin Se/Zn1-xout Mgxout Se quantum well heterostructure are determined using the model solid theory. The heavy hole exciton binding energies are investigated with various Mg alloy contents. The effect of mismatch between the dielectric constants between the well and the barrier is taken into account. The dependence of the excitonic transition energies on the geometrical confinement and the Mg alloy is discussed. Non-linear optical properties are determined using the compact density matrix approach. The linear, third order non-linear optical absorption coefficient values and the refractive index changes of the exciton are calculated for different concentrations of magnesium. The results show that the occurred blue shifts of the resonant peak due to the Mg incorporation give the information about the variation of two energy levels in the quantum well width.

关键词： interband emission energy exciton binding energy quantum well