Decoherence remains one of the most serious challenges to the implementation of quantum technology. It appears as a result of the transformation over time of a quantum superposition state into a classical mixture due to the quantum system interacting with the environment. Since quantum systems are never completely isolated from their environment, decoherence therefore cannot be avoided in realistic situations. Decoherence has been extensively studied, mostly theoretically, because it has many important implications in quantum technology, such as in the fields of quantum information processing, quantum communication, and quantum computation. Here we report a novel experimental scheme on the study of decoherence of a two-mode squeezed vacuum state via its second harmonic generation signal. Our scheme can directly extract the decoherence of the phase-sensitive quantum correlation $\ensuremath{\langle}\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{b}\ensuremath{\rangle}$ between two entangled modes $a$ and $b$ . Such a correlation is the most important characteristic of a two-mode squeezed state. More importantly, this is an experimental study on the decoherence effect of a squeezed vacuum state, which has been rarely investigated.Decoherence remains one of the most serious challenges to the implementation of quantum technology. It appears as a result of the transformation over time of a quantum superposition state into a classical mixture due to the quantum system interacting with the environment. Since quantum systems are never completely isolated from their environment, decoherence therefore cannot be avoided in realistic situations. Decoherence has been extensively studied, mostly theoretically, because it has many important implications in quantum technology, such as in the fields of quantum information processing, quantum communication, and quantum computation. Here we report a novel experimental scheme on the study of decoherence of a two-mode squeezed vacuum state via its second harmonic generation signal. Our scheme can directly extract the decoherence of the phase-sensitive quantum correlation $\ensuremath{\langle}\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{b}\ensuremath{\rangle}$ between two entangled modes $a$ and $b$. Such a correlation is the most important characteristic of a two-mode squeezed state. More importantly, this is an experimental study on the decoherence effect of a squeezed vacuum state, which has been rarely investigated.

arXiv:2012.11839Physical Review ResearchJul 27, 202120 citations

Quantum Decoherence of the Relative Position Between Two Atoms in the Two-mode Squeezed States

Yang Liu

By the full quantum theory,the dynamical evolution of the motion of C.M of two atoms in the two-mode squeezed vacuum states was studied.Through caculating,the reduced density matrix of the relative position of two atoms and decoherence factor were obtained.It was found out:1)the spontaneous radiation of the couple of atoms could induce the decoherence for the motion of C.M in the two-mode squeezed vacuum state;2)the phenomenon of quantum decoherence became more clear with the squeezed factor changing bigger.By the full quantum theory,the dynamical evolution of the motion of C.M of two atoms in the two-mode squeezed vacuum states was studied.Through caculating,the reduced density matrix of the relative position of two atoms and decoherence factor were obtained.It was found out:1)the spontaneous radiation of the couple of atoms could induce the decoherence for the motion of C.M in the two-mode squeezed vacuum state;2)the phenomenon of quantum decoherence became more clear with the squeezed factor changing bigger.

Journal of Jimei UniversityJan 1, 20080 citations

Reduction of Quantum Phase Fluctuations in a Laser Via Squeezed Vacuum Reservoir

Muhammad Suhail Zubairy, Javed Anwar, Shi-Yao Zhu

Springer eBooksJan 1, 19961 citation

Decoherence of the two-mode squeezed vacuum state in a diffusion process

LU Dao-ming

We have studied the case in which one mode of the light field in the two-mode squeezed vacuum state evolves in a diffusion channel. By virtue of thermo-entangled state representation and the technique of integration within an ordered product, the evolution formula of the field density operator is given. Its non-classical properties, such as squeezing effect, antibunching effect, the violation of Cauchy–Schwartze inequality and the entanglement property between two modes, are studied. The influences of the squeezing parameter and the dissipation time on the non-classical properties are discussed. The results obtained by the numerical method show that its non-classical properties are all weakened with the dissipation. On the other hand, its squeezing effect and the entanglement property between two modes are strengthened, but its antibunching effect and the violation of Cauchy–Schwartze inequality are weakened with the increase of the squeezing parameter.We have studied the case in which one mode of the light field in the two-mode squeezed vacuum state evolves in a diffusion channel. By virtue of thermo-entangled state representation and the technique of integration within an ordered product, the evolution formula of the field density operator is given. Its non-classical properties, such as squeezing effect, antibunching effect, the violation of Cauchy–Schwartze inequality and the entanglement property between two modes, are studied. The influences of the squeezing parameter and the dissipation time on the non-classical properties are discussed. The results obtained by the numerical method show that its non-classical properties are all weakened with the dissipation. On the other hand, its squeezing effect and the entanglement property between two modes are strengthened, but its antibunching effect and the violation of Cauchy–Schwartze inequality are weakened with the increase of the squeezing parameter.

Journal of Modern OpticsMay 7, 20190 citations

Phase properties of the two-mode squeezed vacuum states

Ts. Gantsog, R. Tanaś

Physics Letters AJan 1, 199136 citations

a

and

b

. Such a correlation is the most important characteristic of a two-mode squeezed state. More importantly, this is an experimental study on the decoherence effect of a squeezed vacuum state, which has been rarely investigated.