The energy level structure of a variety of one-dimensional confining potentials and the effects of a local singular perturbation

Motivated by current interest in quantum confinement potentials, especially with respect to the Stark spectroscopy of new types of quantum wells, we examine several novel one-dimensional singular oscillators. A Green function method is applied, the construction of the necessary resolvents is reviewed and several new ones are introduced. In addition, previous work on the singular harmonic oscillator model, introduced by Avakian et al. (Phys. Lett. A, 124, 233 (1987). doi:10.1016/0375-9601(87)90627-X0) is reproduced to verify the method and results. A novel feature is the determination of the spectra of asymmetric hybrid linear and quadratic potentials. As in previous work, the singular perturbations are modeled by delta functions.

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Photoreflectance investigations of the energy level structure in GaInNAs-based quantum wells

Journal of Physics Condensed Matter ◽

10.1088/0953-8984/16/31/006 ◽

2004 ◽

Vol 16 (31) ◽

pp. S3071-S3094 ◽

Cited By ~ 44

Author(s):

J Misiewicz ◽

R Kudrawiec ◽

K Ryczko ◽

G S k ◽

A Forchel ◽

...

Keyword(s):

Energy Level ◽

Quantum Wells ◽

Level Structure ◽

Energy Level Structure

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The Exact Determination of the Effective Domain of Dependence of a One-dimensional Numerical Prediction Formula

Tellus ◽

10.3402/tellusa.v6i2.8726 ◽

1954 ◽

Vol 6 (2) ◽

pp. 165-169

Author(s):

Louis Berkofsky

Keyword(s):

Numerical Prediction ◽

Prediction Formula ◽

One Dimensional ◽

Exact Determination ◽

Effective Domain

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Determination of the basic parameters of pseudomorphic GaInAs quantum wells by means of simultaneous transport and optical investigations

Solid-State Electronics ◽

10.1016/0038-1101(94)90271-2 ◽

1994 ◽

Vol 37 (4-6) ◽

pp. 665-667 ◽

Cited By ~ 8

Author(s):

E. Litwin-Staszewska ◽

F. Kobbi ◽

M. Kamal-Saadi ◽

D. Dur ◽

C. Skierbiszewski ◽

...

Keyword(s):

Quantum Wells ◽

Basic Parameters

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Improved thin-layer chromatographic determination of phospholipids in gastric aspirate from newborns, for assessment of lung maturity.

Clinical Chemistry ◽

10.1093/clinchem/34.4.736 ◽

1988 ◽

Vol 34 (4) ◽

pp. 736-738 ◽

Cited By ~ 5

Author(s):

D Serrano de la Cruz ◽

E Santillana ◽

A Mingo ◽

G Fuenmayor ◽

A Pantoja ◽

...

Keyword(s):

Thin Layer ◽

Fetal Lung ◽

Chromatographic Determination ◽

Solvent Mixture ◽

Gastric Aspirate ◽

One Dimensional ◽

Acetic Acid Water ◽

Chromatographic Resolution ◽

Lung Maturity

Abstract This one-dimensional thin-layer chromatographic method is used for assay of phospholipids in the gastric aspirate of newborns. The solvent mixture (chloroform/hexane/methanol/glacial acetic acid/water, 12/7/4/3/0.3 by vol) completely resolves lecithin, sphingomyelin, phosphatidylinositol, phosphatidylserine, phosphatidylethanolamine, and phosphatidylglycerol. The method is simple, precise, inexpensive, and rapid (chromatographic development takes less than 25 min) and gives high chromatographic resolution. We used this method to determine the lecithin/sphingomyelin densitometric ratio (L/S ratio) and the phosphatidylglycerol percentage in 200 samples of gastric aspirate and found an L/S ratio of 2.5 to be a satisfactory cutoff value for distinguishing fetal lung maturity and immaturity. We confirmed that the presence of phosphatidylglycerol excluded the possibility of respiratory distress.

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Energy level structure of Sc42

Nuclear Physics ◽

10.1016/0029-5582(65)90491-8 ◽

1965 ◽

Vol 62 (3) ◽

pp. 434-448 ◽

Cited By ~ 28

Author(s):

J.W. Nelson ◽

J.D. Oberholtzer ◽

H.S. Plendl

Keyword(s):

Energy Level ◽

Level Structure ◽

Energy Level Structure

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Interpretation of the vibrational energy level structure of the astructural molecular ion H5+ and all of its deuterated isotopomers

The Journal of Chemical Physics ◽

10.1063/1.4946808 ◽

2016 ◽

Vol 144 (15) ◽

pp. 154309 ◽

Cited By ~ 22

Author(s):

János Sarka ◽

Attila G. Császár

Keyword(s):

Energy Level ◽

Vibrational Energy ◽

Level Structure ◽

Vibrational Energy Level ◽

Energy Level Structure ◽

Molecular Ion

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Energy-level structure of two-dimensional electrons confined at theAlxGa1−xAs/GaAs interface studied by photoluminescence excitation spectroscopy

Physical Review B ◽

10.1103/physrevb.43.5035 ◽

1991 ◽

Vol 43 (6) ◽

pp. 5035-5038 ◽

Cited By ~ 15

Author(s):

Q. X. Zhao ◽

Y. Fu ◽

P. O. Holtz ◽

B. Monemar ◽

J. P. Bergman ◽

...

Keyword(s):

Energy Level ◽

Level Structure ◽

Two Dimensional ◽

Photoluminescence Excitation ◽

Energy Level Structure

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A Purely Spectroscopic Technique for Determining Energy Band Offsets in Quantum Wells

MRS Proceedings ◽

10.1557/proc-240-99 ◽

1991 ◽

Vol 240 ◽

Cited By ~ 1

Author(s):

Emil S. Koteies

Keyword(s):

Quantum Wells ◽

Valence Band ◽

Accurate Determination ◽

Energy Difference ◽

Spectroscopic Technique ◽

Band Offsets ◽

Band Energy ◽

Semiconductor Quantum Wells ◽

Sensitive Function

ABSTRACTWe have developed a novel experimental technique for accurately determining band offsets in semiconductor quantum wells (QW). It is based on the fact that the ground state heavy- hole (HH) band energy is more sensitive to the depth of the valence band well than the light-hole (LH) band energy. Further, it is well known that as a function of the well width, Lz, the energy difference between the LH and HH excitons in a lattice matched, unstrained QW system experiences a maximum. Calculations show that the position, and more importantly, the magnitude of this maximum is a sensitive function of the valence band offset, Qy, which determines the depth of the valence band well. By fitting experimentally measured LH-HH splittings as a function of Lz, an accurate determination of band offsets can be derived. We further reduce the experimental uncertainty by plotting LH-HH as a function of HH energy (which is a function of Lz ) rather than Lz itself, since then all of the relevant parameters can be precisely determined from absorption spectroscopy alone. Using this technique, we have derived the conduction band offsets for several material systems and, where a consensus has developed, have obtained values in good agreement with other determinations.

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Formalism for the determination of intermediate stress gradients using X-ray diffraction

Journal of Applied Crystallography ◽

10.1107/s0021889809004300 ◽

2009 ◽

Vol 42 (2) ◽

pp. 192-197 ◽

Cited By ~ 3

Author(s):

Thomas Gnäupel-Herold

Keyword(s):

Lattice Strain ◽

Narrow Line ◽

X Ray Diffraction ◽

Beam Spot ◽

Strain Measurements ◽

One Dimensional ◽

X Ray ◽

Stress Gradients ◽

Shaped Beam

A method is outlined that allows the determination of one-dimensional stress gradients at length scales greater than 0.2 mm. By using standard four-circle X-ray diffractometer equipment and simple aperture components, length resolutions down to 0.05 mm in one direction can be achieved through constant orientation of a narrow, line-shaped beam spot. Angle calculations are given for the adjustment of goniometer angles, and for the effective azimuth and tilt of the scattering vector for general angle settings in a four-circle goniometer. The latter is necessary for the computation of stresses from lattice strain measurements.

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