Macroscopic Rabi-Like Oscillations of Ultracold Atoms in an Asymmetrical Two-Dimensional Magnetic Lattice

TL;DR

This paper demonstrates the existence of macroscopic quantum coherence in ultracold atoms trapped in an asymmetrical two-dimensional magnetic lattice, showing Rabi-like oscillations as a signature of quantum phase coherence.

Contribution

It introduces a method to control tunneling in a 2D magnetic lattice using external magnetic bias fields and identifies Rabi-like oscillations as evidence of macroscopic quantum phase.

Findings

Observation of Rabi-like oscillations indicating macroscopic quantum coherence

Control of tunneling via external magnetic bias fields

Solution of Boson Josephson Junctions equations confirming quantum phase signature

Abstract

We investigate the existence of the $macroscopic$ $quantum$ $phase$ in trapped ultracold quantum degenerate gases, such as Bose-Einstein condensate, in an asymmetrical two-dimensional magnetic lattice. We show the key to adiabatically control the tunneling in the new two-dimensional magnetic lattice by means of external magnetic bias fields. The macroscopic quantum phase signature is identified as a Rabi-like oscillation when solving the system of coupled time-dependent differential equations, described here by the Boson Josephson Junctions (BJJs). In solving the system of the BJJs we used an order parameter that includes both time-dependent variational parameters which are the fractional population at each lattice site and the phase difference. The BJJs solution presents a clear evidence for the macroscopic quantum coherence.