A topological realization of spin polarization through vortex formation in collisions of Bose-Einstein condensates

Abstract

The global spin polarization of hadrons in heavy ion collisions has been measured in STAR (the Solenoidal Tracker At Relativistic heavy ion collider) experiments, which opens up a new window in the study of the hottest, least viscous and most vortical fluid that has ever been produced in the laboratory. We present a different approach to spin polarization from conventional ones: a topological realization of spin polarization through quantum vortex formation in collisions of Bose-Einstein condensates (BEC). This approach is based on the observation that the vortex is a topological excitation in a superfluid in presence of local orbital angular momentum and is an analogue of spin degrees of freedom. The formation processes of vortices and vortex-antivortex pairs are investigated by solving the Gross-Pitaevskii Equation with a large-scale parallel algorithm on Graphics Processing Unit (GPU) to very high precision. In a rotating environment, the primary vortex with winding number one is stable against perturbation, which has a minimal energy and fixed orbital angular momentum (OAM), but the vortices with larger winding numbers are unstable and will decay into primary vortices through a redistribution of the energy and vorticity. The injection of OAM can also be realized in non-central collisions of self-interacting condensates, part of the OAM of the initial state will induce the formation of vortices through concentration of energy and vorticity density around topological defects. Different from a hydrodynamical description, the interference of the wave function plays an important role in the transport of energy and vorticity, reflecting the quantum nature of the vortex formation process. The study of the vortex formation may shed light on the nature of particle spin and spin-orbit couplings in strong interaction matter produced in heavy-ion collisions.

arXiv commentPublished in: Phys.Fluids 34 (2022) 8, 087118

References in corpus (71)

• Vortices in a Bose-Einstein Condensate
• Cosmic strings
• Cosmological Experiments in Condensed Matter Systems
• Global $\Lambda$ hyperon polarization in nuclear collisions: evidence for the most vortical fluid
• QCD at finite isospin density
• Spontaneous vortices in the formation of Bose-Einstein condensates
• Globally Polarized Quark-gluon Plasma in Non-central A+A Collisions
• Angular momentum conservation in heavy ion collisions at very high energy
• Topological vortex formation in a Bose-Einstein condensate
• Relativistic distribution function for particles with spin at local thermodynamical equilibrium
• Global polarization of $\Lambda$ hyperons in Au+Au collisions at $\sqrt{s_{{}_{NN}}}$ = 200 GeV
• Observation of vortex phase singularities in Bose-Einstein condensates
• Global hyperon polarization at local thermodynamic equilibrium with vorticity, magnetic field and feed-down
• Non-thermal fixed points: effective weak-coupling for strongly correlated systems far from equilibrium
• Gravitational Bose-Einstein condensation in the kinetic regime
• Theory of Dark Matter Superfluidity
• Spontaneous creation of Kibble-Zurek solitons in a Bose-Einstein condensate
• Rotating quark-gluon plasma in relativistic heavy ion collisions
• Polarization probes of vorticity in heavy ion collisions
• Pion Superfluidity and Meson Properties at Finite Isospin Density
• Vortex Formation by Interference of Multiple Trapped Bose-Einstein Condensates
• Global $\Lambda$ polarization in heavy-ion collisions from a transport model
• Global quark polarization in non-central $A+A$ collisions
• Polarization and Vorticity in the Quark Gluon Plasma
• Relativistic hydrodynamics for spin-polarized fluids
• Vortical fluid and $\Lambda$ spin correlations in high-energy heavy-ion collisions
• Shear-induced spin polarization in heavy-ion collisions
• Lambda Polarization in Peripheral Heavy Ion Collisions
• Polarization of massive fermions in a vortical fluid
• QCD-like Theories at Finite Baryon and Isospin Density
• Bose--Einstein Condensation and Thermalization of the Quark Gluon Plasma
• Angular Momentum and Vortex Formation in Bose-Einstein-Condensed Cold Dark Matter Haloes
• Local polarization and isothermal local equilibrium in relativistic heavy ion collisions
• Probing vorticity structure in heavy-ion collisions by local $\Lambda$ polarization
• Generating spin polarization from vorticity through nonlocal collisions
• Thermal vorticity and spin polarization in heavy-ion collisions
• Flow Vorticity in Peripheral High Energy Heavy Ion Collisions
• Nonthermal fixed points, vortex statistics, and superfluid turbulence in an ultracold Bose gas
• Nonthermal fixed points and the functional renormalization group
• Universality far from equilibrium: From superfluid Bose gases to heavy-ion collisions
• Spin-dependent distribution functions for relativistic hydrodynamics of spin-1/2 particles
• What can we learn from global spin alignment of $\varphi$ meson in heavy-ion collisions?
• Defect formation beyond Kibble-Zurek mechanism and holography
• Derivation of the nonlocal collision term in the relativistic Boltzmann equation for massive spin-1/2 particles from quantum field theory
• Thermodynamic versus kinetic approach to polarization-vorticity coupling
• Superfluid Turbulence: Nonthermal Fixed Point in an Ultracold Bose Gas
• Bose condensation far from equilibrium
• Dark Matter Superfluidity and Galactic Dynamics
• Critical Dynamics of a Two-dimensional Superfluid near a Non-Thermal Fixed Point
• From Kadanoff--Baym to Boltzmann equations for massive spin-1/2 fermions
• Splitting of a doubly quantized vortex through intertwining in Bose-Einstein condensates
• Three-flavor Nambu--Jona-Lasinio model at finite isospin chemical potential
• Vortex nucleation as a case study of symmetry breaking in quantum systems
• Strongly anomalous non-thermal fixed point in a quenched two-dimensional Bose gas
• Improved quark coalescence model for spin alignment and polarization of hadrons
• Global and local spin polarization in heavy ion collisions: a brief overview
• Dynamics of Vortex Formation in Merging Bose-Einstein Condensate Fragments
• Vortices and waves in light dark matter
• A microscopic description for polarization in particle scatterings
• Inhomogeneous Kibble-Zurek mechanism: vortex nucleation during Bose-Einstein condensation
• Vorticity and Spin Polarization in Heavy Ion Collisions: Transport Models
• Decay of quantised vorticity by sound emission
• Polarized secondary particles in unpolarized high energy hadron-hadron collisions?
• Polarization in relativistic fluids: a quantum field theoretical derivation
• Global polarization effect and spin-orbit coupling in strong interaction
• Off-equilibrium infrared structure of self-interacting scalar fields: Universal scaling, Vortex-antivortex superfluid dynamics and Bose-Einstein condensation
• Quantum hydrodynamics of the spinor Bose-Einstein condensate at non-zero temperatures
• 3-dimensional QCD phase diagram with pion condensate in the NJL model
• Reproduction of vortex lattices in the simulations of rotating liquid helium-4 by numerically solving the two-fluid model using smoothed-particle hydrodynamics incorporating vortex dynamics
• Acoustic radiation from vortex-barrier interaction in atomic Bose-Einstein condensate
• Kinetics of hydrodynamic pions in chiral perturbation theory