arXiv subjects

Aranya B. Bhattacherjee

Publications and source records attributed to Aranya B. Bhattacherjee.

23 records · Page 2Linked to original sources

arXiv2008

Faraday instability in a two-component Bose Einstein condensate

Motivated by recent experiments on Faraday waves in Bose Einstein condensates (BEC) we investigate the dynamics of two component cigar shaped BEC subject to periodic modulation of the strength of the transverse confinement. It is shown that two coupled Mathieu equations govern the dynamics of the system. We found that the two component BEC in a phase mixed state is relatively more unstable towards pattern formation than the phase segregated state.

cond-mat.other↗

arXiv2008

Superfluid properties of a Bose-Einstein condensate in an optical lattice confined in a cavity

We study the effect of a one dimensional optical lattice in a cavity field with quantum properties on the superfluid dynamics of a Bose-Einstein condensate(BEC). In the cavity the influence of atomic backaction and the external driving pump become important and strongly modify the optical potential. Due to the strong coupling between the condensate wavefunction and the cavity modes, the cavity light field develops a band structure. This study reveals that the pump and the cavity emerges as a new handle to control the superfluid properties of the BEC.

cond-mat.stat-mech↗

arXiv2004

Quantum theory of vortex lattice state in a rotating Bose-Einstein condensate

We study system of large number of singly quantized vortices in a rotating Bose-Einstein condensate. Analogous to the Meissner effect in superconductors, we show that the vector potential due to the external rotational field can be tuned to cancel the vector potential due to the Magnus field, resulting in a zero average angular momentum and a shear modulus of the vortex lattice. The vortex lattice state exhibits two states, namely, an elastic state and a plastic state. A clear distinction between these states is controlled by the filling fraction, which is the ratio of the number of bosons to the average number of vortices.

cond-mat.stat-mech↗

arXiv2004

Tkachenko modes and quantum melting of Josephson junction type of vortex array in rotating Bose-Einstein condensate

Using path integral formalism, we show that the Abrikosov-Tkachenko vortex lattice may equivalently be understood as an array of Josephson junctions. The Tkachenko modes are found to be basically equivalent to the low energy excitations (Goldstone modes) of an ordered state. The calculated frequencies are in very good agreement with recent experimental data. Calculations of the fluctuations of the relative displacements of the vortices show that vortex melting is a result of quantum fluctuations around the ordered state due to the low energy excitations (Tkachenko modes)and occurs when the ratio of the kinectic energy to the potential energy of the vortex lattice is 0.001.

cond-mat.stat-mech↗

arXiv2003

Rotational bosonic current in a quasi-condensate confined in an optical toroidal trap

We investigate the possibility of inducing a bosonic current which is rotational in a pseudo 1D quasi-condensate confined in an optical toroidal trap. The stability of such a current is also analyzed using hydrodynamics approach. We find that such a current is uniform when the circular symmetry is preserved and energetically stable when the modes of elementary excitations are restricted to one dimension. This scheme allows to distinguish between a quasi and a true condensate by measuring the rotational spectra of the sample.

cond-mat.stat-mech↗