Entanglement and quantum phase transitions

Pedro Ribeiro, Yasser Omar, Vitor Rocha Vieira

Tosihide H. YOSIDA, Ji-Xuan Hou

In this paper we study the quantum phase transition and entanglement in s1=1/2 and s2=1 spin pair system by the exact diagonalization method. We show that, for this exactly solvable quantum bi-spin system, entanglement appears before quantum phase transition and disappears after it. Moreover, we show that the von Neumann entropy, as a measure of entanglement, can reveal quantum phase transition in this system.

Si Li

By use of the exact diagonalization method, the quantum phase transition and en- tanglement in a 6-Li atom system are studied. It is found that entanglement appears before the quantum phase transition and disappears after it in this exactly solvable quantum system. The present results show that the von Neumann entropy, as a measure of entanglement, may reveal the quantum phase transition in this model.

Yang Min-Fong

Shi-Jian Gu, Tian Guang-Shan, Hai-Qing Lin

We examine several well-known quantum spin models and categorize the behaviour of pairwise entanglement at quantum phase transitions. A unified picture on the connection between the entanglement and quantum phase transition in spin systems is presented.

Rolando D. Somma, Howard Barnum, Emanuel H. Knill +2 more