Quantum phases of atomic boson-fermion mixtures in optical lattices
Quantum phases of atomic boson-fermion mixtures in optical lattices
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DOI：
10.1103/physreva.69.021601
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发表时间：
2003-10
影响因子：
2.9
通讯作者：
R. Roth;K. Burnett
中科院分区：
文献类型：
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作者：
R. Roth;K. Burnett
在玻色-费米-哈伯德模型的框架下，研究了一维光学晶格中玻色原子和费米子原子二元混合体系的零温相图。通过精确数值解的相关特征值问题，基态可观测量和响应的外部相位扭曲的评估。相位变化下的刚度提供了玻色子超流分数和费米子德鲁德重量的措施。几个不同的量子相位被确定为排斥玻色子和玻色子费米子相互作用的强度的函数。除了玻色子莫特绝缘相，其他两个绝缘相被发现，其中玻色子超流分数和费米子德鲁德重量同时消失。其中一个双绝缘体相表现出晶体对角长程有序，而另一个的特点是两个物种的空间分离。
The zero-temperature phase diagram of a binary mixture of bosonic and fermionic atoms in a one-dimensional optical lattice is studied in the framework of the Bose-Fermi-Hubbard model. By exact numerical solution of the associated eigenvalue problems, ground state observables and the response to an external phase twist are evaluated. The stiffnesses under phase variations provide measures for the boson superfluid fraction and the fermionic Drude weight. Several distinct quantum phases are identified as functions of the strength of the repulsive boson-boson and the boson-fermion interactions. In addition to the bosonic Mott-insulator phase, two other insulating phases are found, where both the bosonic superfluid fraction and the fermionic Drude weight vanish simultaneously. One of these double-insulator phases exhibits a crystalline diagonal long-range order, while the other is characterized by spatial separation of the two species.