Communications in Theoretical Physics
New Normally Ordered Four-Mode Squeezing Operator for Standard Squeezing of Four-Mode Quadratures
Fan Hong-Yi, Cao He-Lin
Abstract
By virtue of the technique of integration within an ordered product of operators a new four-mode squeezing operator that squeezes the four-mode quadrature operators of light field in the standard way is found. This operator differs from the direct product of two two-mode squeezing operators. It is the exponential operator V ≡exp [ i r ( Q 1 P 2 + Q 2 P 3 + Q 3 P 4 + Q 4 P 1 )]. The Wigner function of the new four-mode squeezed state is calculated, which quite differs from that of the direct-product state of two usual two-mode squeezed states.