Entanglement in many body systems

Xiang-Ping Liao, Mao-Fa Fang, Zheng Xiao-Juan +1 more

We study three-body entanglement induced by spontaneous emission in a three two-level atoms system by using the entanglement tensor approach. The results show that the amount of entanglement is strongly dependent on the initial state of the system and the species of atoms. The three-body entanglement is the result of the coherent superposition of the two-body entanglements. The larger the two-body entanglement is, the stronger the three-body entanglement is. On the other hand, if there exists a great difference in three two-body entanglement measures, the three-body entanglement is very weak. We also find that the maximum of the two-body entanglement obtained with nonidentical atoms is greater than that obtained with identical atoms via adjusting the difference in atomic frequency.

Hannu Christian Wichterich

Bi Si

The entangled state of quantum human body was studied surrounding the microcosmic field of digital human body. The main contents are the state of quantum human body and the entangled state of quantum human body. The former included the density functor, density matrix of quantum human body and the density matrix of mixed state of human body system. The last one included the self spinning entangled state of two particles in which the the quantum human body self spinning was 1/2 and Bell base, the photon polarization state and double photon entangled state of human body system, the fixed field feature and latent variable of human body system, the application of it in human body system information, the measurement of quantum human body state and Winger function. It provided theoretical and experimental gist for the microcosmic study of digital human body.

Frank Verstraete

Ugo Marzolino

Z. Y. Xie, Jialin Chen, Ji-Feng Yu +3 more

Tensor networks are used to represent the wave functions of quantum many-body systems, but the standard approaches only consider two-body entanglement and do not work well for ``frustrated'' systems, where the underlying lattice geometry makes three- or many-body entanglement also important. A new tensor-network approach based on a novel tensor concept for describing such ``simplex'' entanglement shows great promise.