Quantum liquids without symmetry breaking : theories of geometrical phases and their applications

量子液体是物质的特征相，没有任何基本的对称性破缺。然后通常非常成功的基于序参数的标准技术对表征不再有效。为了对量子液体进行分类，我们利用量子力学几何相（Berry连接）构建了物质相理论。我们通过计算Berry相和chen数，将这些一般理论应用于具体的量子系统，并成功地清晰地表征了经典无特征相。

Quantum liquids are characteristic phases of matter that do no have any fundamental symmetry breaking. Then usually quite successful standard techniques based on order parameters are anymore not effective for the characterization. In order to classify the quantum liquids, we have constructed a theory of material phases using quantum mechanical geometrical phases (Berry connections). We have applied these general theories for concrete quantum systems by calculating the Berry phases and Chern numbers and successfully characterized classically featureless phases clearly.