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Full-Text Articles in Physics
A Valence-Bond Operator Algebra For Quantum Spin Models And Its Applications, Huu Tran Do
A Valence-Bond Operator Algebra For Quantum Spin Models And Its Applications, Huu Tran Do
Electronic Theses and Dissertations
The Heisenberg Hamiltonian is the prototype model for quantum magnetism. The Hamilto- nian includes exchange couplings between vector spins, which are the intrinsic magnetic moments of localized electrons. The classical energy between any pair of interacting spins can be minimized by aligning them parallel (ferromagnetic case) or antiparallel (antiferromagnetic), depending on the sign of the coupling. But quantum fluctuations play a key role, and a full quantum mechanical treatment of the many-body system is generally required. Finding the exact ground-state energy and wave function of isotropic antiferromagnetic (AFM) systems for an arbitrary spin-S and lattice morphology is still a challenging …
Experimental Investigation Of Impurities And Their Effect On Acousto-Electric Properties Of Lithium Niobate, Chandrima Chatterjee
Experimental Investigation Of Impurities And Their Effect On Acousto-Electric Properties Of Lithium Niobate, Chandrima Chatterjee
Electronic Theses and Dissertations
No abstract provided.
High Temperature And Pressure Resonant Ultrasound Spectroscopy Study Of Metal Hydride Systems, Rasheed Adebisi
High Temperature And Pressure Resonant Ultrasound Spectroscopy Study Of Metal Hydride Systems, Rasheed Adebisi
Electronic Theses and Dissertations
The goal of this dissertation is to characterize the elastic properties of palladium hydride near the tri-critical point as a classic example of metal hydride systems using the resonant ultrasound spectroscopy. A high temperature and high pressure resonant ultrasound spectroscopy system which include the RUS cell and the direct contact transducer set-up was designed and constructed. The temperature and pressure dependent of elastic moduli of palladium hydride and palladium crystals were obtained at five isotherms near the critical temperature, 293 °C and for pressure range of 250–500 psi. A strong softening of the shear modulus was observed at temperature and …