arXiv subjects

Arup Banerjee

Publications and source records attributed to Arup Banerjee.

22 records · Page 2Linked to original sources

arXiv2001

Comment on relationship between atomic squeezed and entangled states

The ability of parameter recently proposed by Sorensen et al. (Nature, 409, 63 (2001)) to characterize entanglement or inseparability is investigated for a system of two two-level atoms interacting with a single mode of radiation field. For comparison we employ the necessary and sufficient criterion of Peres and Horodecki for inseparability of bipartite states. We show that for diagonal atomic density matrix the parameter of Sorensen et al. fails to show entangled nature of collective atomic state whereas same state is inseparable in accordance with Peres-Horodecki criterion.

quant-ph↗

arXiv2000

A study of trapped Bose gas beyond mean-field theory

We study the ground-state properties of dilute Bose gas confined to both isotropic and anisotropic traps to assess the accuracy of Gross-Pitaevskii (GP) theory. To go beyond GP approximation we use Huang-Yang theory of interatomic interaction energy for hard-sphere Bose gas and use a variational method to solve the resulting modified GP equation. We also make an analytic estimate of the corrections due to higher-order terms in the interatomic interaction energy. We find that the corrections are of the order of 1 percent. However, there is a qualitative change in the density profile due to presence of logarithimic term in the interaction energy for large N (number of atoms)

cond-mat↗

arXiv2000

Frequency dependent hyperpolarizabilities of atoms; calculations using density-functional theory

Using the orbitals generated by the van Leeuwen-Baerends potential, we calculate frequency dependent response properties of noble gas atoms of He, Ne and Ar and alkaline earth atoms Be and Mg, with particlar emphasis on their nonlinear polarizabilities. For this we employ time-dependent Kohn-Sham formalism with adiabatic local-density aproximation (ALDA) for exchange and correlation. We show that results thus obtained for frequency dependent polarizabilities of the inert gas atoms are highly acurate. On the other hand, polarizabilities of the alkaline earths are not given with the same accuracy. In light of this, we make an assessment of ALDA for obtaining linear and nonlinear response properties by employing time-dependent density-functional theory.

physics.atom-ph↗

arXiv2000

Hydrodynamic approach to TDDFT; response properties of metal clusters

Performing electronic structure calculations for large systems, such as nanoparticles or metal clusters, via orbital based Hartree-Fock or Kohn-Sham theories is computationaly demanding. To study such systems, therefore, we have taken recourse to the hydrodynaic approach to time-dependent density functonal theory. In this paper we develop variation-perturbation method within this theory in terms of the particle and the current densities of a system. We then apply this to study the linear and nnlinear resonse properties of alkali metal clusters within spherical jellium backgrond model.

cond-mat↗