标题： 光学晶格中绝缘态由于集体声子激发的不稳定性 显示英文标题

标题： Instability of insulating states in optical lattices due to collective phonon excitations

摘要： 集体声子激发在光学晶格中冷原子特性中的作用被研究。 这些声子激发是集体激发，其出现是由位点间原子相互作用关联原子引起的，没有这种相互作用就不会出现。 这些集体激发不应与由外力产生的晶格振动混淆。 没有假设这样的力。 但所考虑的声子是纯粹自组织的集体激发，由于位点间原子相互作用，表征原子在晶格位点周围的振荡。 结果表明，这些激发可以显著影响原子被局域化的可能性。 在没有声子激发的情况下本应是绝缘态的状态，当考虑到这些激发时可能会变得非局域化。 这适用于长程以及局部原子相互作用。 为了表征稳定区域，使用了伦德曼准则。 显示英文摘要

摘要： The role of collective phonon excitations on the properties of cold atoms in optical lattices is investigated. These phonon excitations are collective excitations, whose appearance is caused by intersite atomic interactions correlating the atoms, and they do not arise without such interactions. These collective excitations should not be confused with lattice vibrations produced by an external force. No such a force is assumed. But the considered phonons are purely self-organized collective excitations, characterizing atomic oscillations around lattice sites, due to intersite atomic interactions. It is shown that these excitations can essentially influence the possibility of atoms to be localized. The states that would be insulating in the absence of phonon excitations can become delocalized when these excitations are taken into account. This concerns long-range as well as local atomic interactions. To characterize the region of stability, the Lindemann criterion is used.