Naslov
Inversion-symmetry breaking in spin patterns by a weak magnetic field

Autori
Krešić, I. ; Robb, G. R. M. ; Labeyrie, G. ; Kaiser, R. ; Ackemann, T.

Izvornik
Physical Review A (2469-9926) 99 (2019), 5; 053851-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
nonlinear-optics, pattern-formation

Sažetak
Laser-driven cold atoms near a plane retroreflecting mirror exhibit self-organization above a pump threshold. We analyze the properties of self-organized spin patterns in the ground state of cold rubidium atoms. Antiferromagnetic patterns in zero magnetic field give way to ferrimagnetic patterns if a small longitudinal field is applied. We demonstrate how the experimental system can be modeled as spin-1 atoms diffractively coupled by the light reflected by the mirror. The roles of both dipolar and quadrupolar magnetization components in determining the threshold and symmetry variations with a weak longitudinal magnetic field are examined. Although the magnetic structures correspond dominantly to a lattice of magnetic dipoles, the symmetry breaking to ferrimagnetic structures in a finite field is mediated by the coupling to a homogenous quadrupole (alignment), which is not possible in a spin-1/2 system. Our study provides a basis for further exploration of instabilities in driven multilevel systems with feedback.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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