Spectral and transport properties of time-periodic PT -symmetric tight-binding lattices
Spectral and transport properties of time-periodic PT -symmetric tight-binding lattices
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DOI：
10.1103/physreva.87.022119
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发表时间：
2013-02
影响因子：
2.9
通讯作者：
G. Valle;S. Longhi
中科院分区：
文献类型：
--
作者：
G. Valle;S. Longhi
研究了一维紧束缚晶格上时间周期$\mathcal{PT}$-对称哈密顿量的谱性质和动力学特征.它示出了一个高频调制下，可以驱动系统的破$\mathcal{PT}$和未破$\mathcal{PT}$相之间的过渡。在不间断的-$\mathcal{PT}$制度的时间周期调制的结果在一个显着的扩大quasienergy spectrum，导致超弹道传输制度。此外，附近的$\mathcal{PT}$-对称性破缺的晶格带的色散曲线成为线性的，与量子波包扩展的强烈减少。
We investigate the spectral properties and dynamical features of a time-periodic $\mathcal{PT}$-symmetric Hamiltonian on a one-dimensional tight-binding lattice. It is shown that a high-frequency modulation can drive the system under a transition between the broken-$\mathcal{PT}$ and the unbroken-$\mathcal{PT}$ phases. The time-periodic modulation in the unbroken-$\mathcal{PT}$ regime results in a significant broadening of the quasienergy spectrum, leading to a hyperballistic transport regime. Also, near the $\mathcal{PT}$-symmetry breaking the dispersion curve of the lattice band becomes linear, with a strong reduction of quantum wave-packet spreading.