Spontaneous symmetry breaking of a ferromagnetic superfluid in a gradient field
1 ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology 08860 Castelldefels (Barcelona), Spain
2 ICREA, Institució Catalana de Recerca i Estudis Avançats - 08015 Barcelona, Spain
Received: 10 June 2015
Accepted: 7 September 2015
We consider the interaction of a ferromagnetic spinor Bose-Einstein condensate with a magnetic-field gradient. The magnetic-field gradient realizes a spin-position coupling that explicitly breaks time-reversal symmetry and space parity , but preserves the combined symmetry. We observe, using numerical simulations, a phase transition spontaneously breaking this remaining symmetry. The transition to a low-gradient phase, in which gradient effects are frozen out by the ferromagnetic interaction, suggests the possibility of high-coherence magnetic sensors unaffected by gradient dephasing.
PACS: 67.85.Fg – Multicomponent condensates; spinor condensates / 64.60.Ej – Studies/theory of phase transitions of specific substances
© EPLA, 2015