TPPC weekly seminar (in-person): Mudit Jain - "Polarized condensates: from cosmology to laboratory"

Wednesday 28 Feb 2024, 12:30 → 14:00 Europe/London

Strand Building, S7.06

Speaker: Mudit Jain (KCL)

Title: Polarized condensates: from cosmology to laboratory

Abstract: Bose-Einstein condensates (BECs), consisting of spin-0 particles, are prevalent in various areas of physics. In this seminar, I will delve into the realm of BECs comprising non-zero spin particles, capable of carrying macroscopic intrinsic spin angular momentum. These objects are naturally present in the spectrum of massive integer spin field theories (examples, in the case of spin-1, will include Proca, Abelian Higgs, and Yang-Mills-Higgs), and hold significance both in cosmological contexts and laboratory environments.

Within cosmology, such condensates are relevant, for instance, in dark photon dark matter, and can form at various epochs in cosmic history depending upon the vector field’s formation mechanism. In dark matter halos (and even in the simple case of spin-0), they arise inevitably via kinetic condensation through the interplay of gravitational and other possible point-like self-interactions, which I shall elucidate in some detail.

In laboratory setups, such BECs comprise ultracold atoms that have non-zero hyperfine spin levels. I will outline a proposal wherein atoms are confined under a uniform bias magnetic field alongside a suitably tuned sinusoidal quadrupole magnetic field. Thanks to the hyperfine spin-magnetic field coupling (Zeeman coupling), the effective system morphs into that of a scalar "charged" particle confined to a spherical surface, with an "electrically polarized magnetic monopole" at the center, facilitating the creation of synthetic Dirac strings.