There's lots of entanglement to find in TLLs :)

Can we observe entanglement between the collective motion of 10,000 atoms with that of another 10,000 atoms? 🤔 We explore this question in our recent arXiv manuscript.

Quantum entanglement is one of the most fascinating predictions of quantum mechanics. When multiple objects are entangled, information is not stored in any individual part, but rather it is stored in their correlations. Entanglement is not only fundamentally important, but it is also a resource for various technologically relevant tasks such as sensing, communication, and computing. Entanglement between two or a few particles has been demonstrated in many labs around the world. But can we demonstrate entanglement between two spatially separated quantum many-body systems consisting of many particles? Entanglement in many-particle systems is notoriously challenging to observe. It usually requires the system to have extremely low temperatures. Even when entanglement is there, measuring and certifying it is difficult because one typically only has access to coarse-grain measurements.

In this paper, we theoretically investigate entanglement between two separated one-dimensional (1D) Bose gases, each consisting of around 10,000 atoms. We show that excitations (i.e. motions) in two spatially separated 1D Bose gases can be made entangled with each other even at finite temperatures, and we derive analytically the threshold temperature below which this entanglement persists. Interestingly, this entanglement is found to scale linearly with the size of each subsystem (extensive); the longer each subsystem is, the more entangled they become without compromising their locality structure. Another exciting thing is that the threshold temperature and the measurement required to witness this extensive entanglement are already accessible in the present-day experiments!

Written by: Taufiq Murtadho