http://localhost:8081/jspui/handle/123456789/124 Mon, 19 Oct 2026 21:03:56 GMT 2026-10-19T21:03:56Z http://localhost:8081/jspui/handle/123456789/21743 Title: A Monte Carlo study of two dimensional Ising magnet CrI3. Authors: Aakash Abstract: The presence of magnetic order in a layered 2D material is one of the great discoveries. A few years back, the presence of magnetic order in lower dimensional materials (1D or 2D) was not possible according to the Mermin-Wagner theorem, but the presence of a finite gap in the spectrum indicates a magnetic phase transition[22]. This report is a study of the ferromagnetic phase transition in a monolayer of chromium tri-iodide (CrI3). Chapter result-II shows the ferromagnetic phase transition in a monolayer of CrI3. We have started with chapter 1, in which we have described the history, method of production, and experimental detection of magnetism in the monolayer of CrI3 very briefly. After that, in Chapter 2, we discussed the layered ”CrI3” crystal structure, bond length, magnetic moment, etc. In chapter 3, we have studied some of the impor tant magnetic models, mainly the Ising model, because we are working only on the Ising model, followed by the Monte Carlo simulation and algorithm discussed in chapter 4. After that, we applied Monte Carlo simulation to square lattice and honeycomb lattice, and the results are presented in Chapter 5. Chapter 6 discusses some of the magnetic anisotropies that are responsible for the magnetic order in two-dimensional materials, and the final results for the monolayer of CrI3 are presented in Chapter 7. In the next chapter (chapter 8), we will analyse the results in various ways, like how we obtained the variation of specific heat with temperature for different lattice sizes. We have also plotted the variation of specific heat with temperature for different values of anisotropic constants to observe the effect of the anisotropic constant on the results. In the next section, we have presented the results for the monolayer of CrCl3, CrBr3, and CrI3 and a comparison between them to observe the effect of non-magnetic ions on the results. In chapter 9, the ferromagnetic phase transition is explained in great detail. We obtained the best fit (using polynomial fit) for our original magnetization curve. In the last chapter, we have listed all the results, conclusions drawn from the results, and a summary of the entire work. Sun, 01 May 2022 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/21743 2022-05-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/21742 Title: Exploring algorithms for quantum computing of atomic nuclei Authors: Gupta, Aman Abstract: Quantum Computation techniques have been used to solve the Deuteron problem namely to obtain the eigenstates and eigenvalues of the groundstate of Deuteron. 2 encoding schemes(JWT and GC) are discussed to convert the Hamiltonian into sum weighted Pauli matrices. 3 quantum algorithms(VQE, QPE and DPE) are explored to obtain the desired properties. Modified QPE was also introduced to obtain the eigenstate by performing adiabatic time evolution of a guess state. These are algorithms are created such that it can be used to any nuclear many-body physics problems. Sun, 01 May 2022 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/21742 2022-05-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/21741 Title: ELECTRICAL AND OPTICAL HEATING OF WAVELENGTH SELECTIVE MICRORING SWITCH Authors: Maury, Amit Kumar Abstract: GST (Ge2Sb2Te5) is a phase change material that has recently gained attention as a potential materials for photonic devices due of their fast write and read speeds, high scalability, reversible phase change, excellent data storage, storage capacity on many levels and low power consumption. Electrical and optical heating of phase change materials (GST) embedded silicon microring with a high visual contrast during the GST phase shift investigate and analyse, Also in the GST amorphous phase has a high thermo-optic coefficient. Extinction ratios of 18.8 dB and 25.6 dB achieved at through and drop ports, respectively. In electrical and optical heating, GST’s resonance wavelength shift of almost 0.66 nm/µm and 0.40 nm/µm per unit length of GST, respectively achieved . Tuning efficiency in electrical and optical tuning is almost 0.86 nm/mW and 1.05 nm/mW, respectively. The tuning range in electrical and optical configuration is almost 4.57 nm and 4.04 nm, respectively for the LGST = 7 µm. Finally the time domain analysis of amorphization and crystallization for 1 µm to 7 µm length of GST presented. In optical heating 80% fall time down in amorphous to crystalline is 54.53 ns and time to reach at room temperature is 1421.04 ns for the 1 µm length of GST. For crystalline to amorphous 80% fall time down in optical heating is 36.02 ns and time to reach at room temperature is 1006.51 ns for the 1 µm length of GST. The same device can also be suitably used for tunable wavelength switch and Wavelength Selective optical power attenuator. A maximum attenuation of around 19 dB at wavelength around 1545 nm at through port with 1 µm length of GST with only 0.6 mW and 1.53 mW power consumption in electrical and optical heating cases achieved. Fri, 01 Apr 2022 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/21741 2022-04-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/21740 Title: Studies of Scintillation Mechanism and Proportionality Curve by Rate Equations Authors: Mandal, Arijit Abstract: A high energetic electron deposits energy in scintillator materials by the creation of electron-hole pair order of 1020 but we get the light output Photon order of 104.There are subsequent linear and nonlinear interactions involve within the materials.The radiative recombination has a non linear relation with the created primary electron energy. This non- proportionality relation reduces the scintillation resolution. We use here a system of coupled rate equations and apply it to scintillator LaBr3:Ce, CSI and NaI at Room temperature.The model is solved considering the transportation path of the carriers as cylindrical and the results are compared of these materials and total light yield for those materials. The space and time distributions of carriers have been studied to examine the response of non-proportionality. This study will give a detailed theoretical insight of the scintillator mechanism which will help to discover and fabrication of a smart scintillator with both a high light yield, better-energy resolution, small non-proportionality, and fast rise and decay time. Fri, 01 Apr 2022 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/21740 2022-04-01T00:00:00Z