Non-equilibrium physics of spinor quantum fluids

Lauren Aycock, Srivatsan Chakram, Mukund Vengalattore

Ceren B. Dağ, Sheng-Tao Wang, Luming Duan

Weysi, Martin

The definitive non-equilibrium ground state of the driven-dissipative quantum fluid, previously identified as a turbulent correlated liquid, is hereby revealed to be the terminal phase of an intrinsic, deterministic decay cascade. High-fidelity spinor Gross-Pitaevskii simulations prove that the system’s true initial state is a metastable soliton. This state inevitably decays via a newly discovered, transient ”hyper-ordered” intermediate lattice phase before fracturing into the final turbulent liquid attractor. This three-stage mechanistic pathway (Soliton → Hyper-Ordered Lattice → Turbulence) is shown to be a universal and fundamental property of the non-local spinor dynamics, supplanting previous phenomenological descriptions with a rigorous, mechanistic proof.

Dan Stamper-Kurn, Masahito Ueda

Spinor Bose gases form a family of quantum fluids manifesting both magnetic order and superfluidity. This article reviews experimental and theoretical progress in understanding the static and dynamic properties of these fluids. The connection between system properties and the rotational symmetry properties of the atomic states and their interactions are investigated. Following a review of the experimental techniques used for characterizing spinor gases, their mean-field and many-body ground states, both in isolation and under the application of symmetry-breaking external fields, are discussed. These states serve as the starting point for understanding low-energy dynamics, spin textures and topological defects, effects of magnetic dipole interactions, and various non-equilibrium collective spin-mixing phenomena. The paper aims to form connections and establish coherence among the vast range of works on spinor Bose gases, so as to point to open questions and future research opportunities.

Alberto Bramati, Michele Modugno

F. Becattini, Matteo Buzzegoli, Eduardo Grossi

In this work the non-equilibrium density operator approach introduced by Zubarev more than 50 years ago to describe quantum systems at local thermodynamic equilibrium is revisited. This method - which was used to obtain the first ''Kubo" formula of shear viscosity, is especially suitable to describe quantum effects in fluids. This feature makes it a viable tool to describe the physics of the Quark Gluon Plasma in relativistic nuclear collisions.