We propose a form of spontaneous symmetry breaking driven by zero-point quantum fluctuations. To be specific, we consider the low-energy dynamics of a mixture of two species of spin-1 Bose gases. It is demonstrated that the quantum fluctuations lift a degeneracy regarding the relative orientations of the spin directors of the two species and result in correlation or locking between these macroscopic variables. This locking persists in the presence of the trapping potential and weak magnetic fields, allowing, in principle, an experimental probe of this correlated spontaneous symmetry breaking as a macroscopic manifestation of zero-point quantum fluctuations.

• Received 18 September 2013
• Revised 15 January 2014

DOI:https://doi.org/10.1103/PhysRevA.89.043623