Search or add a thesis

Advanced Search (Beta)
Home > Ladder Operators, Inherent Algebras and Associated Coherent States for Position-Dependent Mass Systems

Ladder Operators, Inherent Algebras and Associated Coherent States for Position-Dependent Mass Systems

Thesis Info

Access Option

External Link

Author

Naila Amir

Program

PhD

Institute

National University of Sciences & Technology

City

Islamabad

Province

Islamabad

Country

Pakistan

Thesis Completing Year

2015

Thesis Completion Status

Completed

Subject

Natural Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/6710/1/Naila_Amir_Maths_NUST_2015.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726573941

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Position-dependent effective mass systems are of great significance due to the fact that these models have numerous applications in various areas of physics. The qualitative understanding of a complicated realistic system can be acquired by analyzing the exact solutions of a related simplified model. However, the quantization of position-dependent effective mass systems and finding their solutions, involve some conceptual and mathematical difficulties of a fundamental nature. The factorization method provides us with a powerful tool for obtaining solutions and the underlying algebraic structure of the exactly solvable systems. The underlying algebra of a system has vast applications in different areas of mathematics and physics, such as it plays an important role in the theory of coherent states. Coherent states are extremely useful in various areas such as quantum mechanics, quantum optics, quantum information and group theory. In this thesis, position-dependent effective mass systems are studied in the context of their quantization, finding the solutions, construction of the algebraic structure and associated coherent states. In the first part of the thesis we mainly focus on quantizing and obtaining the exact solutions of the systems with spatially varying mass. The next part deals with the construction of the ladder operators and the inherent algebra of the pertaining systems. The associated coherent states and their properties are presented in the final part of the thesis. Beside the traditional way of obtaining exact solutions by solving the Schrödinger equation there exists another elegant method to solve the systems algebraically by factorizing the corresponding Hamiltonian. This method is based on supersymmetric quantum mechanics and the integrability condition, commonly known as shape invariance. After quantizing the position-dependent effective mass system, this factorization technique is used to determine the energy spectrum and the corresponding wave functions. For the sake of completeness the iv Abstract v method of solving a time-independent Schrödinger equation with spatially varying mass is also discussed. Considering a non-linear harmonic oscillator as an illustrative example, it is shown that both the above procedures produce the same results. The property of shape invariance enables us to obtain the ladder operators of the confining system. A general recipe for the construction of the ladder operators and inherent algebra for the position-dependent effective mass systems is presented. In order to exemplify the general formalism, a non-linear harmonic oscillator together with several other examples of the shape invariant systems with position-dependent effective mass is considered. Explicit expressions for the ladder operators and the associated algebra are presented. Using the ladder operators and the underlying algebra, the coherent states for the positiondependent effective mass systems are constructed and their properties are analyzed. In particular, we emphasize on various kinds of coherent states for a non-linear harmonic oscillator with spatially varying mass. By realizing SU(1; 1) as the dynamic group of the system, the construction of Barut-Girardello coherent states is presented. In addition, an algebraic independent kind of coherent states, namely Gazeau-Klauder coherent states, are also constructed. The statistical properties of Barut-Girardello and Gazeau-Klauder coherent states are investigated by means of the Mandel parameter and the second order correlation function. Moreover, the temporal evolution of the Gazeau-Klauder coherent states is analysed by means of autocorrelation function. It is shown that these states mimic the phenomena of quantum revivals and fractional revivals during their time evolution.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

میں ول ول تکناں مرشد نوں

میں ول ول تکنا مرشد نوں
مار گیا سوہنیا ایہہ مینوں تیرا پیار وے
دل کرے میں ویکھاں تینوں بار بار وے

تیریاں اداواں مینوں بڑا ای ستاندیاں
جدوں یاد آوے تیری بڑا ای رواندیاں
اکھیاں وی ہر ویلے مینہ برساندیاں
جے توں آویں فیر آوے دل نوں قرار وے
مار گیا سوہنیا اے مینوں تیرا پیار وے

جدوں دا میں ویکھا تینوں ہوش میری بھل گئی
چھڈ کاروبار میں تاں گلیاں چ رُل گئی
سارے بھار ہولے ہوئے ککھاں نال تُل گئی
مینوں چنگی لگی تیرے کجلے دی دھار وے
مار گیا سوہنیا اے مینوں تیرا پیار وے

مکھ تیرا ایویں جیویں چن اسمانی اے
ویکھے جو وی ہک واری ہووے اوہ دیوانی اے
اجڑیاں دلاں اُتے ہووے مہربانی اے
ہک واری دے جا مینوں اپنا دیدار وے
مار گیا سوہنیا اے مینوں تیرا پیار وے

تینوں جد تکیا تے میں تیری ہوئی وے
جگ وچ تیرے جیہا دسدا نہ کوئی وے
مینوں سد لے توں میرا یار ’’سنگوئی‘‘ وے
تیرا اوتھے رج رج کراں گی دیدار وے
مار گیا سوہنیا اے مینوں تیرا پیار وے

قادریؔ سائیں ہن نہ گھبرا توں
ٹلے جا کے مندراں وی گل وچ پا توں
جوگی بن در در بین بجا توں
خلق کرے گی فیر تیرے نال پیار وے
مار گیا سوہنیا اے مینوں تیرا پیار وے

علم مختلف الحدیث پر امام شافعی کے تفکرات کا تحقیقی مطالعہ

After the era of Prophet Muhammad (S.A.W), there were dissimilarities in interpretations of contradictive revelations by Muhammad (S.A.W) thereby questioning their authentication while being considered a basic source of extracting the Sharia acts. In this context, Imam Shāfʿī studies all the dissimilarities and contradictions and devised finest principles which performed very positive role in rationalizing the conflicting Ahadiths. He was first to discuss these matters in an innovative manner. It is therefore, essential for investigator to refer to Shāfʿīs principles to rationalize any Hadith lying under contradiction. Imam Shāfʿī stated that Hadith is not itself contradicting but its apparent meaning leads the investigator into misconception. Consequently, he has stated three methods to remove this conflict. First is the combination (جمع) which recommends working on both Ahadiths at the same time rather than leaving either of them. Second is the abrogation (تنسیخ) which requires extensive knowledge of Quran and History before inferring the final decision of Muhammad (S.A.W) and scholars widely recommend Imam Shāfiʿī in recognizing abrogated Ahadiths. Third is preference (ترجيح) which is based upon peripheral attributes.

Modeling and Control of Underground Coal Gasification

Modeling and Control of Underground Coal Gasification Pakistan is going through an acute energy crisis despite being blessed by huge energy potential. Pakistan has approximately 185 billion tonnes of coal, of which 175 billion tonnes of Lignite B is located in Thar. The most suitable technology to harness the potential of the Thar coal reservoirs is the underground coal gasification (UCG), which involves the underground conversion of coal in to synthetic gas that can be used in numerous industrial applications. Therefore, the planning commission of Pakistan allocated the Block V of Thar coal field to UCG project Thar, in order to setup a pilot project. This research work deals with the modeling and control of Thar coal gasifier. In this research work a computer model is developed for the underground gasification of Block V of the Thar coal field. The numerical solution of the model is carried out by incorporating a pseudo steady state approximation, which replaces gas phase PDEs with ODEs with respect to the length of the reactor. This approximation assumes that the concentration of the gases attain steady steady before any significant change occurs in the densities of coal and char. The PDEs for the densities of coal and char and solid temperature are solved by finite difference method, while the gas phase ODEs are simultaneously solved as a boundary value problem, marching from inlet to outlet. The simulation results show that the solution of the model is capable of providing space and time profiles for different physical quantities, such as, coal and char densities, concentration and molar fractions of different gases, rate of different chemical reactions and solid and gas temperatures. A detailed parametric study is also carried out for the model solution, which shows that the composition of the product gas is sensitive to various coal properties and operating conditions. The parametrization of a complex process like UCG is a formidable job, which includes a large number of physical and chemical properties of coal, different operating conditions and various in situ phenomena. In order to determine the composition of coal and char, the ultimate analysis of their samples is carried out. The results of the ultimate analysis are prone to uncertainty, because the measurements are obtained from different coal samples, which go through different handling procedures before they are analyzed.