Dependence of valence‐subband dispersion relations on heterointerface boundary conditions in InxGa1−xAsyP1−y/InP narrow quantum wells

1994 ◽  
Vol 76 (4) ◽  
pp. 2347-2356 ◽  
Author(s):  
Takayuki Yamanaka ◽  
Hidehiko Kamada ◽  
Yuzo Yoshikuni ◽  
Wayne W. Lui ◽  
Shunji Seki ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Quantum Wells ◽  
Dispersion Relations

Nonlinear TE surface waves in a ferrite slab bounded by Kerr-type metamaterials

2017 ◽  
Vol 26 (03) ◽  
pp. 1750028 ◽  
Author(s):  
Burhan Zamir ◽  
Rashid Ali
Keyword(s):  
Boundary Conditions ◽  
Surface Waves ◽  
Transverse Electric ◽  
Dispersion Relations ◽  
Double Negative ◽  
Propagation Characteristics ◽  
Special Cases ◽  
Tangential Field ◽  
Effective Wave ◽  
Ferrite Slab

In this paper, nonlinear transverse electric surface waves in a structure consisting of a ferrite slab sandwiched between a Kerr-type double-negative metamaterial (DNG-MTM) have been investigated. In addition to a DNG-MTM, two special cases with nonlinear single-negative metamaterials (SNG-MTMs) have also been discussed. The dispersion relations are obtained by applying the boundary conditions to the tangential field components of each layer. The propagation characteristics are plotted numerically for the effective wave index versus propagation frequency.

Interface Boundary Conditions and Nonparabolicity Effects in Quantum Wells

1988 ◽  
Vol 148 (2) ◽  
pp. K113-K117 ◽  
Author(s):  
M. De Dios Leyva ◽  
J. López Gondar ◽  
J. Sabin Del Valle
Keyword(s):  
Boundary Conditions ◽  
Quantum Wells ◽  
Interface Boundary ◽  
Interface Boundary Conditions

ZnSe-ZnCdSe single quantum wells: dispersion relations and absorption processes

1997 ◽  
Vol 43 (1-3) ◽  
pp. 133-136
Author(s):  
P. Bigenwald ◽  
B. Gil ◽  
L. Konczewicz ◽  
P. Testud
Keyword(s):  
Quantum Wells ◽  
Dispersion Relations ◽  
Single Quantum

Dispersion Relations of Heavily Doped Quantum Wells

2016 ◽  
Vol 5 (4) ◽  
pp. 427-472 ◽  
Author(s):  
K. P. Ghatak ◽  
K. Sarkar ◽  
N. Debbarma ◽  
L. Suraj Singh
Keyword(s):  
Quantum Wells ◽  
Dispersion Relations ◽  
Heavily Doped

scholarly journals Quantum Confinement of Chiral Charge Carriers in Ring Conductors

2021 ◽  
Author(s):  
◽  
Lei Yang
Keyword(s):  
Angular Momentum ◽  
Quantum Wells ◽  
Quantum Confinement ◽  
Berry Phase ◽  
Correction Term ◽  
Single Layer ◽  
Energy Shift ◽  
Dispersion Relations ◽  
Single Layer Graphene ◽  
Quantum Ring

<p>We theoretically study the quantum confinement effects and transport prop- erties of quantum ring (QR) systems. In particular, we investigate QRs made out of the following materials: single-layer graphene (SLG), single- layer transition-metal dichalcogenides (TMDs) and narrow-gap semiconduc- tor quantum wells (SQWs).  Via perturbation theory and assuming that the ring aspect ratio is small, the general subband dispersion relations of these hard-wall ring confined systems are determined. These dispersion results agree with and extend on previous works. We discover the necessity of including both a size-quantisation energy and an angular momentum dependent energy shift to the dispersion equation due to their sizeable impact on the conductance of the system.  The topological properties of these QR systems is also investigated. We find that QR confinement of materials may destroy the topologically non-trivial properties of states. The topological phase can be recovered when the band structure is inverted and the confined material parameters satisfy certain critical widths and gap limits.  An analytical expression of the conductance for QRs (with symmetrically- arranged leads), in the presence of the perpendicular magnetic field piercing the centre of the ring, is derived. We study the geometric (i.e. Berry) and dynamic phases of the system that arise from the interference of partial waves in the ring branches. We discover that the Berry phase is modified by a correction term that arises purely from the quantum confinement of the materials. This has generally not been taken into account by previous studies. The explicit analytical expressions of the phase correction term are derived and shown to be proportional to the angular momentum dependent energy shift, present in the dispersion relations, for lead injection energies close to the subband energy.  Overall, this study finds that the material-dependent phase plays a significant role in both the dispersion relation and the conductance of QRs and thus provides a useful insight for future experimental efforts with regards to transport in QR systems.</p>

Dispersion of Waves in Composite Laminates With Transverse Matrix Cracks, Finite Element and Plate Theory Computations

1998 ◽  
Vol 65 (3) ◽  
pp. 588-595
Author(s):  
M. A˚berg ◽  
P. Gudmundson
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Composite Laminates ◽  
Plate Theory ◽  
Plate Thickness ◽  
Composite Plates ◽  
Dispersion Relations ◽  
Finite Element Program ◽  
Periodic Cell ◽  
Matrix Cracks

Dispersion relations for laminated composite plates with transverse matrix cracks have been computed using two methods. In the first approach it is assumed that the matrix cracks appear periodically and hence it is possible to consider a periodic cell of the structure using Bloch-type boundary conditions. This problem was formulated in complex notation and solved in a standard finite element program (ABAQUS) using two identical finite element meshes, one for the real part and one for the imaginary part of the displacements. The two meshes were coupled by the boundary conditions on the cell. The code then computed the eigenfrequeneies of the system for a given wave vector. It was then possible to compute the phase velocities. The second approach used may be viewed as a two step homogenization. First the cracked layers are homogenized and replaced by weaker uncracked layers and then the standard first-order shear-deformation laminate theory is used to compute dispersion relations. Dispersion relations were computed using both methods for three glass-fiberepoxy laminates ([0/90]2,[0/90]sand[0/45/-45]s with cracks in the 90 and ±45 deg plies). For the lowestflexural mode the difference in phase velocity between the methods was less then five percent for wavelengths longer than two times the plate thickness. For the extensional mode a wavelength often plate thicknesses gave a five percent difference.

scholarly journals Quantum Confinement of Chiral Charge Carriers in Ring Conductors

2021 ◽  
Author(s):  
◽  
Lei Yang
Keyword(s):  
Angular Momentum ◽  
Quantum Wells ◽  
Quantum Confinement ◽  
Berry Phase ◽  
Correction Term ◽  
Single Layer ◽  
Energy Shift ◽  
Dispersion Relations ◽  
Single Layer Graphene ◽  
Quantum Ring

<p>We theoretically study the quantum confinement effects and transport prop- erties of quantum ring (QR) systems. In particular, we investigate QRs made out of the following materials: single-layer graphene (SLG), single- layer transition-metal dichalcogenides (TMDs) and narrow-gap semiconduc- tor quantum wells (SQWs).  Via perturbation theory and assuming that the ring aspect ratio is small, the general subband dispersion relations of these hard-wall ring confined systems are determined. These dispersion results agree with and extend on previous works. We discover the necessity of including both a size-quantisation energy and an angular momentum dependent energy shift to the dispersion equation due to their sizeable impact on the conductance of the system.  The topological properties of these QR systems is also investigated. We find that QR confinement of materials may destroy the topologically non-trivial properties of states. The topological phase can be recovered when the band structure is inverted and the confined material parameters satisfy certain critical widths and gap limits.  An analytical expression of the conductance for QRs (with symmetrically- arranged leads), in the presence of the perpendicular magnetic field piercing the centre of the ring, is derived. We study the geometric (i.e. Berry) and dynamic phases of the system that arise from the interference of partial waves in the ring branches. We discover that the Berry phase is modified by a correction term that arises purely from the quantum confinement of the materials. This has generally not been taken into account by previous studies. The explicit analytical expressions of the phase correction term are derived and shown to be proportional to the angular momentum dependent energy shift, present in the dispersion relations, for lead injection energies close to the subband energy.  Overall, this study finds that the material-dependent phase plays a significant role in both the dispersion relation and the conductance of QRs and thus provides a useful insight for future experimental efforts with regards to transport in QR systems.</p>

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