Spin squeezing

Spin squeezing is a quantum mechanical phenomenon that relates to the manipulation of quantum states of spin systems. In quantum optics and condensed matter physics, spin squeezing refers to the reduction of uncertainty in one component of the spin of a quantum system, at the expense of increased uncertainty in another component, while maintaining that the total uncertainty remains bounded by the Heisenberg uncertainty principle. To understand spin squeezing, consider a collection of spins (like those of atoms or qubits).