Spontaneous spin bifurcations and ferromagnetic phase transitions in a spinor exciton-polariton condensate
Redondo, Y del Valle-Inclan
Physical Review X
American Physical Society
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Ohadi, H., Dreisman, A., Rubo, Y., Pinsker, F., Redondo, Y. d. V., Tsintzos, S., Hatzopoulos, Z., et al. (2015). Spontaneous spin bifurcations and ferromagnetic phase transitions in a spinor exciton-polariton condensate. Physical Review X, 5 (031002) https://doi.org/10.1103/PhysRevX.5.031002
We observe a spontaneous parity breaking bifurcation to a ferromagnetic state in a spatially-trapped exciton-polariton condensate. At a critical bifurcation density under nonresonant excitation, the whole condensate spontaneously magnetizes and randomly adopts one of two elliptically-polarized (up to 95% circularly-polarized) states with opposite handedness of polarization. The magnetized condensate remains stable for many seconds at 5 K, but at higher temperatures can flip from one magnetic orientation to another. We optically address these states and demonstrate the inversion of the magnetic state by resonantly injecting 100-fold weaker pulses of opposite spin. Theoretically, these phenomena can be well described as spontaneous symmetry breaking of the spin degree of freedom induced by different loss rates of the linear polarizations.
This work was supported by Grants EPSRC No. EP/G060649/1, EU No. CLERMONT4 235114, EU No. INDEX 289968, Spanish MEC (MAT2008-01555), Greek GSRT ARISTEIA Apollo program and Fundación La Caixa, and Mexican CONACYT No. 251808. FP acknowledges financial support through an EPSRC doctoral prize fellowship at the University of Cambridge and a Schrödinger fellowship at the University of Oxford.
European Research Council (320503)
EC FP7 MC ITN (289968)
EC FP7 MC ITN (235114)
External DOI: https://doi.org/10.1103/PhysRevX.5.031002
This record's URL: https://www.repository.cam.ac.uk/handle/1810/248529
Attribution 2.0 UK: England & Wales
Licence URL: http://creativecommons.org/licenses/by/2.0/uk/