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N. J. Kylstra

Publications and source records attributed to N. J. Kylstra.

2 recordsLinked to original sources

Josephson spectroscopy of a dilute Bose-Einstein condensate in a double-well potential

The dynamics of a Bose-Einstein condensate in a double-well potential are analysed in terms of transitions between energy eigenstates. By solving the time-dependent and time-independent Gross-Pitaevskii equation in one dimension, we identify tunnelling resonances associated with level crossings, and determine the critical velocity that characterises the resonance. We test the validity of a non-linear two-state model, and show that for the experimentally interesting case, where the critical velocity is large, the influence of higher-lying states is important.

cond-mat

Transparency Near a Photonic Band Edge

We study the absorption and dispersion properties of a ${\bf Λ}$-type atom which decays spontaneously near the edge of a photonic band gap (PBG). Using an isotropic PBG model, we show that the atom can become transparent to a probe laser field, even when other dissipative channels are present. This transparency originates from the square root singularity of the density of modes of the PBG material at threshold.

quant-ph