arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1706.02797cond-mat.quant-gas
收藏

有限尺寸周期驱动的非线性系统的拓扑相变

Topological phase transitions in finite-size periodically driven translationally invariant systems

Yang Ge, Marcos Rigol

摘要:

众所周知,在热力学极限下,在动量空间中光滑的么正时间演化下,一个非线性不变系统的陈氏数不能改变。然而,陈数的实空间对应物,博特指数,已被证明在具有开放边界条件的周期性驱动系统中发生变化。本文证明了在热力学极限下,在热力学不变系统中,Bott指数和Chern数是一致的。使用的Bott指数,我们表明,在有限大小的几何不变系统,费米海下的周期性驱动器,打开缓慢,可以获得一个不同的拓扑结构从初始状态。这可以发生,提供的热力学极限中的间隙闭合点是不存在的有限系统的离散布里渊区。因此,在这样的系统中,可以使用周期驱动器从拓扑平凡的状态开始动态地准备拓扑非平凡的状态。

英文摘要:

It is known that, in the thermodynamic limit, the Chern number of a translationally invariant system cannot change under unitary time evolutions that are smooth in momentum space. Yet a real-space counterpart of the Chern number, the Bott index, has been shown to change in periodically driven systems with open boundary conditions. Here we prove that the Bott index and the Chern number are identical in translationally invariant systems in the thermodynamic limit. Using the Bott index, we show that, in finite-size translationally invariant systems, a Fermi sea under a periodic drive that is turned on slowly can acquire a different topology from that of the initial state. This can happen provided that the gap-closing points in the thermodynamic limit are absent in the discrete Brillouin zone of the finite system. Hence, in such systems, a periodic drive can be used to dynamically prepare topologically nontrivial states starting from topologically trivial ones.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑