Squeezed spin states and pseudo-Hermitian operators

Abstract

We show that squeezed spin states achieved through nonlinear interactions are eigenstates of a non-Hermitian operator, which however enjoys the property of pseudo-Hermiticity such that the resulting eigenvalues are real. We represent the squeezed states in terms of Wigner d-matrices, making the evaluation of squeezing straightforward. We show that the spin squeezing can go up to 70%.