Demonstrating mesoscopic superpositions in double-well Bose–Einstein condensates

Mesoscopic quantum superpositions in bimodal Bose-Einstein condensates: decoherence and strategies to counteract it

BEC superpositions in twin wells

The idea of a macroscopic entity simultaneously existing in two distinct possible states was introduced by Erwin Schrödinger in 1935, as a Gedanken experimental demonstration of the absurdity of quantum mechanics [1]. Since then, evidence has mounted that reality is as absurd as quantum mechanics suggests, with persistent currents (of a few μA) of opposite circulation having been detected in SQ...

Counting Statistics of a Bose-Einstein Condensate in a Double-Well Potential

This thesis aims to investigate the dynamic properties of ultra-cold Bose-Einstein condensates (BEC) trapped in a deep double well potential. Despite its simplicity, this system shows a rich variety of dynamical behaviors: Josephson oscillations, self-trapping behavior and critical dynamics. In contrast to previous studies, we aim to understand not only the first moment of the evolving occupati...

Vortex phase qubit: generating arbitrary, counterrotating, coherent superpositions in Bose-Einstein condensates via optical angular momentum beams.

We propose a scheme for the generation of arbitrary coherent superpositions of vortex states in Bose-Einstein condensates (BEC) using the orbital-angular-momentum states of light. We devise a scheme to generate coherent superpositions of two such counterrotating states of light using well-known experimental techniques. We show that a specially designed Raman scheme allows for transfer of the op...

Supersolid vortex crystals in Rydberg-dressed Bose-Einstein condensates.

We study rotating quasi-two-dimensional Bose-Einstein condensates, in which atoms are dressed to a highly excited Rydberg state. This leads to weak effective interactions that induce a transition to a mesoscopic supersolid state. Considering slow rotation, we determine its superfluidity using quantum Monte Carlo simulations as well as mean field calculations. For rapid rotation, the latter reve...