论文标题
量子涡流的流体动力特征和光谱特性
Hydrodynamic signatures and spectral properties of the quantum vortex
论文作者
论文摘要
我们使用状态密度（DOS）的标准定义（DOS）和对激发频谱的互补方面敏感的修改版本的标准定义，表征了量子涡流中量子涡流（BEC）中量子涡流的低覆盖激励。事实证明，后者与研究杂质嵌入量子涡流时意识到的极化状态特别相关。我们确定杂质通过其残余kelvon模式以及BEC NAMBU-GOLDSTONE模式的相位波动对涡流的横向波动敏感。涡流的存在产生一个异常的激发光谱，并在低能量下具有有限的能量隙和非线性DOS。我们发现，Kelvon模式对外部电势的高灵敏度提供了对被困在涡流中的杂质的量子级别控制的通道。该额外的控制渠道可能会用于使用涡旋杂质作为量子信息处理的量子单位的建议。
We characterize the low-lying excitations of a quantum vortex in a quasi-two-dimensional Bose-Einstein condensate (BEC) using the standard definition of the density of states (DOS) and a modified version that is sensitive to complementary aspects of the excitation's spectrum. The latter proves to be particularly relevant to studying the polaronic state realized when an impurity is embedded in a quantum vortex. We establish that the impurity becomes sensitive to the transversal fluctuations of the vortex, via its remnant kelvon mode, and to the phase fluctuations of the BEC Nambu-Goldstone mode. The presence of the vortex yields an anomalous excitation spectrum with a finite energy gap and non-linear DOS at low energies. We find that the high sensitivity of the kelvon mode to external potentials provides a channel of quantum-level control over impurities trapped in a vortex. This extra control channel may be of practical use for the proposal of using vortex-trapped impurities as qubit units for quantum information processing.
