Quantum interference spin currents: Atoms, bulk semiconductors, and quantum wells

2002 ◽  
Author(s):  
R.D.R Bhat ◽  
F. Nastos ◽  
Ali Najmaie ◽  
J.E. Sipe
Keyword(s):  
Quantum Wells ◽  
Quantum Interference ◽  
Spin Currents ◽  
Bulk Semiconductors

Pulse-induced quantum interference of intersubband transitions in coupled quantum wells

2004 ◽  
Vol 84 (1) ◽  
pp. 64-66 ◽  
Author(s):  
T. Müller ◽  
W. Parz ◽  
G. Strasser ◽  
K. Unterrainer
Keyword(s):  
Quantum Wells ◽  
Quantum Interference ◽  
Intersubband Transitions ◽  
Coupled Quantum Wells

FIELD-INDUCED QUANTUM INTERFERENCE IN SEMICONDUCTOR QUANTUM WELLS FOR LASING WITHOUT POPULATION INVERSION AND ELECTROMAGNETICALLY INDUCED TRANSPARENCY

1995 ◽  
Vol 04 (02) ◽  
pp. 261-282 ◽  
Author(s):  
Y. ZHAO ◽  
D. HUANG ◽  
C. WU
Keyword(s):  
Quantum Wells ◽  
Quantum Interference ◽  
Population Inversion ◽  
Electromagnetically Induced Transparency ◽  
Random Phase ◽  
Nonlinear Susceptibility ◽  
Double Quantum ◽  
Single Quantum Well ◽  
Semiconductor Quantum Wells ◽  
Induced Transparency

This paper presents the current results of field-induced quantum interference in semiconductor quantum wells. Three-level systems with two conduction subbands in single and double quantum wells coupled by a resonant field are studied. We investigate effects of the Coulomb and field-induced electronic renormalizations of the energy subbands and steady eigenstates of electrons. The random-phase and ladder approximations have been used to calculate the linear interband and intersubband optical absorptions and refractive indices. The effect of collective dipole moment on the nonlinear susceptibility has been incorporated into the study by using a local-field approach. Lasing without population inversion, electromagnetically induced transparency, and enhanced nonlinearity with reduced absorption inside the intersubband-coupled single quantum well and dc-field coupled double quantum wells are found.

Quantum interference of intersubband transitions in coupled quantum wells

1999 ◽  
Vol 5 (1-2) ◽  
pp. 16-26 ◽  
Author(s):  
K.L. Campman ◽  
K.D. Maranowski ◽  
H. Schmidt ◽  
A. Imamoglu ◽  
A.C. Gossard
Keyword(s):  
Quantum Wells ◽  
Quantum Interference ◽  
Intersubband Transitions ◽  
Coupled Quantum Wells

Thermoelectric Properties of PbTe/Pb1−x. Eux Te Quantum Wells

1998 ◽  
Vol 545 ◽  
Author(s):  
H. Scherrer ◽  
Z. Dashevsky ◽  
V. Kantser ◽  
A. Casian ◽  
I. Sur ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Variational Method ◽  
Quantum Wells ◽  
Power Factor ◽  
Thermoelectric Power Factor ◽  
Quantum Well Structures ◽  
Effective Masses ◽  
Dimensional Quantization ◽  
Carrier Scattering ◽  
Bulk Semiconductors

AbstractThe electrical conductivity, Seebeck coefficient, and thermoelectric power factor of PbTe/Pb1−xEuxTe quantum well structures are investigated theoretically. The variational method is employed. The anisotropy of effective masses, the multivalley character of the bulk semiconductors and also the dependence of effective masses in dimensional quantization subbands on the well width are taken into account. The carrier scattering both on optical and acoustical phonons is considered for structures with (111) and (100) crystallographic orientation. It is found that the power factor is larger in (100) oriented quantum wells. The results of recent experiments are discussed.

Optical Spectroscopy of Defects in GaAs/AlGaAs Multiple Quantum Wells.

1993 ◽  
Vol 325 ◽  
Author(s):  
B. Monemar ◽  
P. O. Holtz ◽  
J. P. Bergman ◽  
Q.X. Zhao ◽  
C.I. Harris ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Optical Spectroscopy ◽  
Thermal Emission ◽  
Deep Level ◽  
Free Exciton ◽  
Interface Roughness ◽  
Multiple Quantum ◽  
Nonradiative Recombination ◽  
Decay Times ◽  
Bulk Semiconductors

AbstractThe study of electronic properties of GaAs/AlGaAs quantum wells (QWs) has traditionally been focused on intrinsic phenomena, in particular the free exciton behaviour. Defects and impurities have often been regarded as less relevant compared to the case of bulk semiconductors. Doping in QWs is important in many applications, however, and recently the knowledge about the structure of shallow donors and acceptors from optical spectroscopy has advanced to a level comparable to the situation in bulk semiconductors. A dramatic difference from the bulk case is the common occurrence of localisation effects due to interface roughness in QW structures. The recombination of bound excitons (BEs) differs drastically from bulk, BE lifetimes decrease with decreasing well thickness Lw, but increase with decreasing barrier thickness Lb (at constant Lw) below Lb=70Å. Exciton capture at impurities is a process which is strongly influenced by the localisation potentials from the interface roughness. The recombination process in doped QWs involves a nonradiative component, for shallow acceptors an excitonic Auger process has been identified. Deep nonradiative defects in the (MBE grown) QW as well as in the barrier material are manifested in measurements of the PL decay time vs temperature. In undoped multiple QWs the decay times vs T are consistent with thermal emission out of the well into the barrier, where nonradiative recombination via deep level defects occur. Nonradiative recombination in the well itself can be studied in electron-irradiated structures. Preliminary data also demonstrate the feasibility of hydrogen passivation of dopants as well as deep levels in the QW structures.

Quantum interference effect in double quantum wells

1995 ◽  
Vol 35 (1-3) ◽  
pp. 372-375
Author(s):  
Xinghua Wang ◽  
Qi Yu ◽  
Reino Laiho ◽  
Chengfang Li ◽  
Jian Liu ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Interference Effect ◽  
Quantum Interference ◽  
Double Quantum ◽  
Quantum Interference Effect
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