QUANTUM-FIELDS IN DISEQUILIBRIUM - SQUEEZED STATES

A spacetime description of squeezed states in quantum fields is presen ted, revealing the connection between squeezing and nonequilibrium dyn amics. Squeezings in configuration space, occupation number space, and phase space are distinguished; generating transformations and criteri a for their physical realization are discussed. The results have an im mediate applicability to atoms and ions in traps, as well as to quantu m optics in relativistic and nonequilibrium systems. Squeezing, sub-Po issonian statistics, and antibunching are all shown to be a direct con sequence of spacetime inhomogeneities in the quantum field. The finite speed of communication between separate regions of the field (finite speed of light) places a lower limit on the attainable spectral width of squeezed states. The squeezing parameter for field quadratures has the appearance of a chemical potential in an inhomogeneous field, and through a renormalization may be generated by a Chem-Simons-like term.