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Quantum Order: a Quantum Entanglement of Many Particles

Xiao-Gang Wen
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Abstract

It is pointed out that quantum states, in general, contain a new kind of orders that cannot be characterized by symmetry. A concept of quantum order is introduced to describe such orders. As two concrete examples, we discussed quantum orders in free fermion systems and in 2D spin-1/2 systems. We generalize the Landau's theory for the classical orders and introduce projective symmetry group and Fermi surface topology to characterize different quantum orders.

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Xiao-Gang Wen. 2002-01-29. Quantum Order: a Quantum Entanglement of Many Particles. https://doi.org/10.1016/s0375-9601(02)00808-3

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