One- and two-axis squeezing of atomic ensembles in optical cavities
One- and two-axis squeezing of atomic ensembles in optical cavities
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DOI：
10.1088/1367-2630/aa8438
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发表时间：
2017-09-28
影响因子：
3.3
通讯作者：
Sorensen, A. S.
中科院分区：
文献类型：
--
作者：
Borregaard, J.;Davis, E. J.;Sorensen, A. S.
在光腔中可获得的强光-物质耦合使得原子系综的高度压缩态的产生成为可能。它是由Sorensen和Molmer(2002 Phys.A 66 022314修订版)如何在腔设置中实现有效的单轴扭转哈密顿量。在这里，我们扩展了这项工作，并展示了如何在类似的腔结构中实现有效的两轴扭转哈密顿量。我们对这两种方案进行了比较，以确定它们的优点。在没有退相干的情况下，双轴哈密顿量比单轴哈密顿量产生更大的压缩。如果受自发辐射和腔衰变的退相干限制，我们发现这两个方案的压缩水平与根NC大致相同，其中C是单原子协作性，N是原子总数。与理想的压缩操作相比，我们发现对于特定的初始态，耗散形式的单轴方案比么正单轴方案或两轴方案具有更高的保真度。然而，对于一般的初始状态，么正单轴和双轴格式表现得更好。
The strong light-matter coupling attainable in optical cavities enables the generation of highly squeezed states of atomic ensembles. It was shown by Sorensen and Molmer (2002 Phys. Rev. A 66 022314) how an effective one-axis twisting Hamiltonian can be realized in a cavity setup. Here, we extend this work and show how an effective two-axis twisting Hamiltonian can be realized in a similar cavity setup. We compare the two schemes in order to characterize their advantages. In the absence of decoherence, the two-axis Hamiltonian leads to more squeezing than the one-axis Hamiltonian. If limited by decoherence from spontaneous emission and cavity decay, we find roughly the same level of squeezing for the two schemes scaling as root NC where C is the single atom cooperativity and Nis the total number of atoms. When compared to an ideal squeezing operation, we find that for specific initial states, a dissipative version of the one-axis scheme attains higher fidelity than the unitary one-axis scheme or the two-axis scheme. However, the unitary one-axis and two-axis schemes perform better for general initial states.