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Full-Text Articles in Physical Sciences and Mathematics
Spontaneous Magnetization And Electron Momentum Density In Three-Dimensional Quantum Dots, R. Saniz, B. Barbiellini, A. B. Denison, A. Bansil
Spontaneous Magnetization And Electron Momentum Density In Three-Dimensional Quantum Dots, R. Saniz, B. Barbiellini, A. B. Denison, A. Bansil
Arun Bansil
We discuss an exactly solvable model Hamiltonian for describing the interacting electron gas in a quantum dot. Results for a spherical square-well confining potential are presented. The ground state is found to exhibit striking oscillations in spin polarization with dot radius at a fixed electron density. These oscillations are shown to induce characteristic signatures in the momentum density of the electron gas, providing a route for direct experimental observation of the dot magnetization via spectroscopies sensitive to the electron momentum density.
Spin Texture On The Warped Dirac-Cone Surface States In Topological Insulators, Susmita Basak, Hsin Lin, L. A. Wray, S. Y. Xu, L. Fu, M. Z. Hasan, A. Bansil
Spin Texture On The Warped Dirac-Cone Surface States In Topological Insulators, Susmita Basak, Hsin Lin, L. A. Wray, S. Y. Xu, L. Fu, M. Z. Hasan, A. Bansil
Arun Bansil
We have investigated the nature of surface states in the Bi₂Te₃ family of three-dimensional topological insulators using first-principles calculations as well as a model Hamiltonian approach. When the surface Dirac cone is warped due to Dresselhaus spin-orbit coupling in rhombohedral structures, the spin acquires a finite out-of-the-plane component. We provide a simple, minimal model to describe the in-plane spin texture of the warped surface Dirac cone observed in experiments where spins are seen to be not aligned perpendicular to the electron momentum. Our k·p model calculation reveals that this in-plane spin texture requires fifth-order Dresselhaus spin-orbit coupling terms
Electron Correlations, Spontaneous Magnetization And Momentum Density In Quantum Dots, A. Bansil, D. Nissenbaum, B. Barbiellini, R. Saniz
Electron Correlations, Spontaneous Magnetization And Momentum Density In Quantum Dots, A. Bansil, D. Nissenbaum, B. Barbiellini, R. Saniz
Arun Bansil
The magnetization of quantum dots is discussed in terms of a relatively simple but exactly solvable model Hamiltonian. The model predicts oscillations in spin polarization as a function of dot radius for a fixed electron density. These oscillations in magnetization are shown to yield distinct signature in the momentum density of the electron gas, suggesting the usefulness of momentum resolved spectroscopies for investigating the magnetization of dot systems. We also present variational quantum Monte Carlo calculations on a square dot containing 12 electrons in order to gain insight into correlation effects on the interactions between like and unlike spins in …