Generalized Bloch oscillations of ultracold lattice atoms subject to higher-order gradients
Generalized Bloch oscillations of ultracold lattice atoms subject to higher-order gradients
复制标题
受高阶梯度影响的超冷晶格原子的广义布洛赫振荡
DOI：
10.1103/physreva.100.053603
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发表时间：
2019
影响因子：
2.9
通讯作者：
Hu Zhong Kun
中科院分区：
文献类型：
--
作者：
Zhu Qian Ru;Chen Shou Long;Li Shao Jun;Fang Xue Ting;Cao Lushuai;Hu Zhong Kun
标准布洛赫振荡通常是指量子粒子在周期晶格中的振荡隧穿动力学加上线性梯度。在这项工作中，我们从理论上研究了存在额外的高阶梯度的广义形式的布洛赫振荡，并证明了高阶梯度可以显着修改隧道动力学，特别是在频谱的密度振荡。标准布洛赫振荡的频谱是由一个单一的主频率和它的高次谐波，而在外部电位的高阶梯度引起的频谱中的精细结构，这些布洛赫频率，这是由一系列的频率峰值。我们的研究对布洛赫振荡测量外力的应用产生了双重后果：一方面，在测量光谱的有限分辨率下，精细结构将表现为光谱的模糊，并导致测量的固有误差。另一方面，由于精细结构可以通过实验分辨，因此可以提供比线性梯度强度更多的外力信息，并可用于测量更复杂的力。
The standard Bloch oscillation normally refers to the oscillatory tunneling dynamics of quantum particles in a periodic lattice plus a linear gradient. In this work we theoretically investigate the generalized form of the Bloch oscillation in the presence of additional higher order gradients, and demonstrate that the higher order gradients can significantly modify the tunneling dynamics, particularly in the spectrum of the density oscillation. The spectrum of the standard Bloch oscillation is composed of a single prime frequency and its higher harmonics, while the higher-order gradients in the external potential give rise to fine structures in the spectrum around each of these Bloch frequencies, which are composed of serieses of frequency peaks. Our investigation leads to a twofold consequence to the applications of Bloch oscillations for measuring external forces: For one thing, under a limited resolution of the measured spectrum, the fine structures would manifest as a blur to the spectrum, and leads to intrinsic errors to the measurement. For another, given that the fine structures could be experimentally resolved, they can supply more information of the external force than the strength of the linear gradient, and be used to measure more complicated forces.