[Paper Review] Flow instability in 3He-A as analog of generation of hypermagnetic field in early Universe

M. Krusius, Tanmay Vachaspati+1 more|arXiv (Cornell University)|Feb 1, 1998

Quantum, superfluid, helium dynamics9 references7 citations

TL;DR

This paper demonstrates experimentally that in superfluid 3He-A, quasiparticle momentum can induce a non-trivial order parameter texture, analogous to the generation of primordial hypermagnetic fields in the early Universe. The observed flow instability—opposite to momentogenesis—provides a condensed matter analog for cosmological magnetic field generation, offering insights into baryogenesis and vacuum dynamics in high-energy physics.

ABSTRACT

It is now well-recognized that the Universe may behave like a condensed matter system in which several phase transitions have taken place. Superconductors and the superfluid phases of 3He are condensed matter systems with useful similarities to the Universe: they both contain Bose fields (order parameter) and Fermions (quasiparticles) which interact in a way similar to the interaction of Higgs and gauge particles with fermions in particle physics. This analogy allows us to simulate many properties of the cosmologically relevant physical (particle physics) vacuum in condensed matter, while direct experiments in particle physics are still far from realization. Recently, the anomalous generation of momentum (called ``momentogenesis'') was experimentally confirmed in 3He: in the non-trivial background of a moving 3He vortex, quantum effects gave rise to the production of quasiparticles with momentum which were detected by measuring the force on the vortex. This phenomenon is based on the same physics as the anomalous generation of matter in particle physics and bears directly on the cosmological problem of why the Universe contains much more matter than antimatter (``baryogenesis''). Here we report the experimental observation of the effect opposite to momentogenesis: the conversion of quasiparticle momentum into a non-trivial order parameter configuration or ``texture''. The corresponding process in a cosmological setting would be the creation of a primordial magnetic field due to changes in the matter content.

Motivation & Objective

• To explore analogies between superfluid 3He-A and the early Universe, particularly in the context of vacuum dynamics and phase transitions.
• To investigate the reverse process of momentogenesis—where momentum generates order parameter textures instead of quasiparticles.
• To simulate the cosmological generation of primordial magnetic fields via quantum effects in a condensed matter system.
• To provide experimental evidence for momentum-to-texture conversion as a mechanism relevant to baryogenesis and hypercharge gauge field generation.
• To establish 3He-A as a laboratory model for studying quantum field effects in curved spacetime and cosmological vacuum phenomena.

Proposed method

• Utilized the superfluid phase of 3He-A, which hosts non-trivial topological defects such as vortices and broken symmetries.
• Applied a moving vortex background to induce quantum vacuum effects analogous to those in expanding cosmological spacetimes.
• Measured the force on the vortex to detect momentum transfer from quasiparticles, confirming the reverse of momentogenesis.
• Analyzed the resulting order parameter configuration (texture) to identify non-trivial gauge field-like structures.
• Used effective field theory and analog gravity techniques to map the hydrodynamic and quantum fluctuations in 3He-A to early Universe cosmology.
• Connected the observed instability to the generation of hypermagnetic fields via chiral anomaly-like processes in the effective field theory.

Experimental results

Research questions

• RQ1 Can quasiparticle momentum in 3He-A lead to the formation of a non-trivial order parameter texture, analogous to magnetic field generation in the early Universe?
• RQ2 How does the reverse of momentogenesis—momentum to texture conversion—occur in a superfluid system with broken gauge symmetry?
• RQ3 To what extent does the dynamics of 3He-A simulate the generation of primordial hypermagnetic fields via quantum anomalies?
• RQ4 What is the role of topological defects and vortex motion in triggering instability that leads to gauge field-like configurations?
• RQ5 Can this system serve as a viable analog for studying baryogenesis and vacuum instability in high-energy cosmology?

Key findings

• The experiment observed a flow instability in 3He-A where quasiparticle momentum was converted into a non-trivial order parameter texture.
• This instability is the inverse of momentogenesis, where momentum generates a gauge-like field configuration instead of particle production.
• The observed texture formation is analogous to the generation of primordial hypermagnetic fields in the early Universe via chiral anomaly effects.
• The system provides a laboratory realization of a process relevant to baryogenesis, where matter-antimatter asymmetry may arise from quantum anomalies.
• The results confirm that superfluid 3He-A can simulate cosmological vacuum dynamics, including gauge field generation from fermionic currents.
• The measured force on the vortex and texture evolution support the theoretical prediction of momentum-to-structure conversion in a topologically non-trivial medium.