Macroscopic Superpositions
(image 1 and 2) Absorption images of two Bose Einstein condensates prepared in a ring lattice, each with a different circulation. (image 3) Ring optical superlattice generated by Laguerre-Gaussian beams.
In 1935, Schrödinger used a gedanken experiment in which a cat was put in a quantum superposition of alive and dead states to demonstrate the limitations of quantum mechanics. The idea remained an academic curiosity until Caldeira and Leggett suggested that indeed a macroscopic object could behave quantum mechanically, provided that it was sufficiently decoupled from its environment. The high controllability offered by cold atoms in an optical lattice and their weak coupling to their environment make them ideal systems for generating quantum superpositions. Recently we have studied ways to generate and probe macroscopic superpositions of Bose Einstein condensates with opposite circulations in rotating-ring superlattices.
PRA 77, 023622 (2008), PRA 75, 063616 (2007).
