Spinor Bose-Einstein condensate as an analog simulator of molecular bending vibrations

TL;DR

This paper shows that spinor Bose-Einstein condensates can simulate molecular bending vibrations, providing insights into quantum phase transitions and entanglement dynamics in a controllable quantum system.

Contribution

It introduces a novel use of spinor BECs as analog simulators for molecular vibrational models, linking quantum phase transitions with entanglement and non-Gaussian sensitivity.

Findings

Spinor BECs can simulate linear and bent molecular configurations.

Dynamical instability leads to entanglement generation.

Scaling of non-Gaussian sensitivity indicates quantum phase transition.

Abstract

We demonstrate that spinor Bose-Einstein condensates (BEC) can be operated as an analog simulator of the two-dimensional vibron model. This algebraic model for the description of bending and stretching vibrations of molecules, in the case of a triatomic molecules, exhibits two phases where linear and bent configurations are stabilised. Spinor BECs can be engineered to simulate states that correspond to linear or bent triatomic molecules, with the BEC's Wigner function encoding information about the molecular configuration. We show how quantum simulations of the bending dynamics of linear molecules can be realized, and how the straightening of a bent molecule leads to a dynamical instability. In the dynamics triggered by the corresponding instability, a significant amount of entanglement is generated, and we characterise the dynamics with the squeezing parameter and the quantum Fisher information (QFI). The scaling of the non-Gaussian sensitivity, described by the difference between squeezing and QFI, grows with the system size once the spinor system crosses from the linear to the bent phase, thus serving as a dynamical witness for the quantum phase transition.