Resonance State Wave Functions of 15^{15}Be using Supersymmetric Quantum Mechanics

The theoretical procedure of supersymmetric quantum mechanics is adopted to generate the resonance state wave functions of the unbound nucleus $^{15}$Be. In this framework, we used a density dependent M3Y microscopic potential and arrived at the energy and width of the 1.8 MeV (5/2$^+$) resonance state. We did not find any other nearby resonances for $^{15}$Be. It becomes apparent that the present framework is a powerful tool to theoretically complement the increasingly important accelerator based experiments with unbound nuclei.Comment: 5 pages, 4 figures, Phys. Lett. B (2017

External Electric Field Mediated Quantum Phase Transitions in One-Dimensional Charge Ordered Insulators: A DMRG Study

We perform density matrix renormalization group (DMRG) calculations extensively on one-dimensional chains with on site (U) as well as nearest neighbour (V) Coulomb repulsions. The calculations are carried out in full parameter space with explicit inclusion of the static bias and we compare the nature of spin density wave (SDW) and charge density wave (CDW) insulators under the influence of external electric field. We find that, although the SDW (U>2V) and CDW (U<2V) insulators enter into a conducting state after a certain threshold bias, CDW insulators require much higher bias than the SDW insulators for insulator-metal transition at zero temperature. We also find the CDW-SDW phase transition on application of external electric field. The bias required for the transitions in both cases decreases with increase in system size.Comment: 7 pages, 7 figures, accepted in J. Phys.: Condens. Matte