Noise in Two Mode Squeezed States and Thermo Field Dynamics

Alexey N. Kireev, A. Mann, M. Revzen +1 more

Kyo Yoshida, Tsuyoshi Hayashi, Sachiko Kitajima +1 more

Jun Zhou, Hong-Yi Fan, Jun Song

We propose a new two-mode thermo- and squeezing-mixed optical field, described by the new density operator ρ = ( 1 − e f − | g | 2 ) e g a † b † e f a † a | 0 ⟩ b b ⟨ 0 | e g ∗ a b , where | 0 ⟩ b b ⟨ 0 | is the b -mode vacuum, e f a † a represents the thermo-field, and e g a † b † indicates squeezing. The photon statistics for ρ is studied by virtue of the method of integration within ordered product (IWOP) of operators. Such a field can be generated when a two-mode squeezed state passes through a one-mode dissipation channel.

R. F. Bishop, Apostol Vourdas

Changchun Wang, Fan Hong‐Yi

We investigate how an initial thermo vacuum state, in the context of thermo field dynamics, evolves in a single-mode amplitude dissipative channel, and find that in this process the thermo squeezing effect decreases while the fictitious-mode vacuum becomes chaotic.

Hong-Yi Fan, Hui Wang

Based on the <η| representation in Thermo Field Dynamics3 we introduce the thermal Wigner operator, with which we reach the conclusion that due to the thermal effect the quantum fluctuation of two-mode squeezed vacuum state increases by a factor cosh 2θ, where tanh θ = exp (-ℏω/2kT). We also mathematically analyse the formalism of Thermo Field Dynamics in the context of entanglement theory.