A-B Transition in Superfluid 3He and Cosmological Phase Transitions

Hindmarsh, Mark and Sauls, J. A. and Zhang, Kuang and Autti, S. and Haley, Richard P. and Heikkinen, Petri J. and Huber, Stephan J. and Levitin, Lev V. and Lopez-Eiguren, Asier and Mayer, Adam J. and Rummukainen, Kari and Saunders, John and Zmeev, Dmitry (2024) A-B Transition in Superfluid 3He and Cosmological Phase Transitions. Journal of Low Temperature Physics, 215 (5-6). pp. 495-524. ISSN 0022-2291

Abstract

First-order phase transitions in the very early universe are a prediction of many extensions of the Standard Model of particle physics and could provide the departure from equilibrium needed for a dynamical explanation of the baryon asymmetry of the Universe. They could also produce gravitational waves of a frequency observable by future space-based detectors such as the Laser Interferometer Space Antenna. All calculations of the gravitational wave power spectrum rely on a relativistic version of the classical nucleation theory of Cahn-Hilliard and Langer, due to Coleman and Linde. The high purity and precise control of pressure and temperature achievable in the laboratory made the first-order A to B transition of superfluid 3He ideal for test of classical nucleation theory. As Leggett and others have noted, the theory fails dramatically. The lifetime of the metastable A phase is measurable, typically of order minutes to hours, far faster than classical nucleation theory predicts. If the nucleation of B phase from the supercooled A phase is due to a new, rapid intrinsic mechanism that would have implications for first-order cosmological phase transitions as well as predictions for gravitational wave production in the early universe. Here we discuss studies of the A-B phase transition dynamics in 3He, both experimental and theoretical, and show how the computational technology for cosmological phase transition can be used to simulate the dynamics of the A-B transition, support the experimental investigations of the A-B transition in the QUEST-DMC collaboration with the goal of identifying and quantifying the mechanism(s) responsible for nucleation of stable phases in ultra-pure metastable quantum phases.