scholarly journals Spin-1/2 Landau levels in the symmetric gauge from the zero energy modes

2018 ◽  
Vol 2 (4) ◽  
pp. 045030 ◽  
Author(s):  
Lucas Sourrouille
2019 ◽  
Vol 21 (7) ◽  
pp. 073013
Author(s):  
Zhi Yang ◽  
Weiwei Chen ◽  
Qunxiang Li ◽  
Q W Shi

2015 ◽  
Vol 15 (10) ◽  
pp. 8263-8266
Author(s):  
S. C. Kim ◽  
Y. H. Jeong ◽  
S.-R. Eric Yang

Graphene Landau levels have discrete energies consisting zero energy chiral states and non-zero energy states with mixed chirality. Each Landau level splits into discrete energies when a localized potential is present. A simple scaling analysis suggests that a localized potential can act as a strong perturbation, and that it can be even more singular in graphene than in ordinary two-dimensional systems of massful electrons. Parabolic, Coulomb, and Gaussian potentials in graphene may have anomalous boundstates whose probability density has a sharp peak inside the potential and a broad peak of size magnetic length l outside the potential. The n = 0 Landau level with zero energy has only one anomalous state while the n = ±1 Landau levels with non-zero energy have two (integer quantum number n is related to the quantized Landau level energies). These anomalous states can provide a new magnetospectroscopic feature in impurity cyclotron resonances of graphene. In the present work we investigate quantitatively the conditions under which the anomalous states can exist. These results may provide a guide in searching for anomalous states experimentally.


Author(s):  
Hiroki Sakamoto ◽  
Yasuhiro Hatsugai ◽  
Hideo Aoki ◽  
Tohru Kawarabayashi

1999 ◽  
Vol 09 (PR10) ◽  
pp. Pr10-223-Pr10-225
Author(s):  
S. Scheidl ◽  
B. Rosenow

2018 ◽  
Vol 8 (1) ◽  
pp. 211-221
Author(s):  
Negar Aminoroayaei ◽  
Bahram Shahedi

In the current century, a suitable strategy is concerned for optimal consumption of energy, due to limited natural resources and fossil fuels for moving towards sustainable development and environmental protection. Given the rising cost of energy, environmental pollution and the end of fossil fuels, zero-energy buildings became a popular option in today's world. The purpose of this study is to investigate the factors affecting the design of zero-energy buildings, in order to reduce energy consumption and increase productivity, including plan form, climatic characteristics, materials, coverage etc. The present study collects the features of zero-energy building in Isfahan, which is based on the Emberger Climate View in the arid climate, by examining the books and related writings, field observations and using a descriptive method, in the form of qualitative studies. The results of the research showed that some actions are needed to save energy and, in general, less consumption of renewable energy by considering the climate and the use of natural conditions.


Author(s):  
G. Gulyamov ◽  
U. I. Erkaboev ◽  
A. G. Gulyamov

The article considers the oscillations of interband magneto-optical absorption in semiconductors with the Kane dispersion law. We have compared the changes in oscillations of the joint density of states with respect to the photon energy for different Landau levels in parabolic and non-parabolic zones. An analytical expression is obtained for the oscillation of the combined density of states in narrow-gap semiconductors. We have calculated the dependence of the maximum photon energy on the magnetic field at different temperatures. A theoretical study of the band structure showed that the magnetoabsorption oscillations decrease with an increase in temperature, and the photon energies nonlinearly depend on a strong magnetic field. The article proposes a simple method for calculating the oscillation of joint density of states in a quantizing magnetic field with the non-quadratic dispersion law. The temperature dependence of the oscillations joint density of states in semiconductors with non-parabolic dispersion law is obtained. Moreover, the article studies the temperature dependence of the band gap in a strong magnetic field with the non-quadratic dispersion law. The method is applied to the research of the magnetic absorption in narrow-gap semiconductors with nonparabolic dispersion law. It is shown that as the temperature increases, Landau levels are washed away due to thermal broadening and density of states turns into a density of states without a magnetic field. Using the mathematical model, the temperature dependence of the density distribution of energy states in strong magnetic fields is considered. It is shown that the continuous spectrum of the density of states, measured at the temperature of liquid nitrogen, at low temperatures turns into discrete Landau levels. Mathematical modeling of processes using experimental values of the continuous spectrum of the density of states makes it possible to calculate discrete Landau levels. We have created the three-dimensional fan chart of magneto optical oscillations of semiconductors with considering for the joint density of energy states. For a nonquadratic dispersion law, the maximum frequency of the absorbed light and the width of the forbidden band are shown to depend nonlinearly on the magnetic field. Modeling the temperature  dependence allowed us to determine the Landau levels in semiconductors in a wide temperature spectrum. Using the proposed model, the experimental results obtained for narrow-gap semiconductors are analyzed. The theoretical results are compared with experimental results.


2014 ◽  
Vol 5 (2) ◽  
pp. 157-166 ◽  
Author(s):  
Cs. Szász

The paper presents an intelligent building (IB) development strategy emphasizing the locally available non-polluting renewable energy resources utilization. Considering the immense complexity of the topic, the implementation strategy of the main energy-flow processes is unfolded, using the net zero-energy building concept (NZEB). Noticeably, in the first research steps the mathematical background of the considered NZEB strategy has been developed and presented. Then careful LabView software-based simulations prove that the adopted strategy is feasible for implementation. The result of the above mentioned research efforts is a set of powerful and versatile software toolkits well suitable to model and simulate complex heating, ventilation and air-conditioning processes and to perform energy balance performance evaluations. Besides the elaborated mathematical models, concrete software implementation examples and measurement data also is provided in the paper. Finally, the proposed original models offer a feasible solution for future developments and research in NZEB applications modelling and simulation purposes.


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