arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1805.04734cond-mat.quant-gascond-mat.str-elquant-ph
收藏

二维费米超流体的量子尺度反常和空间相干性

Quantum scale anomaly and spatial coherence in a 2D Fermi superfluid

Puneet A. Murthy, Nicolò Defenu, Luca Bayha, Marvin Holten, Philipp M. Preiss, Tilman Enss, Selim Jochim

摘要:

量子反常是由量子涨落引起的对经典标度对称性的破坏。虽然它们在量子场论中突出地出现,以正则化不同的物理量,但它们对实验观测值的影响很难辨别。在这里,我们发现了一个惊人的表现,量子异常的动量空间动力学的二维费米超流体的超冷原子。我们测量的位置和对动量分布的超流体在呼吸模式周期的不同的相互作用强度跨越BEC-BCS交叉。而系统表现出自相似的演化在弱相互作用的BEC和BCS限制,我们发现了一个违反在强相互作用的制度。在一阶相干函数中,尺度不变性破缺的特征被增强。特别是,幂律指数,在系统中的远程相位相关的特征被修改,由于这种效果,表明量子异常的临界特性的2D超流体有显着的影响。

英文摘要:

Quantum anomalies are violations of classical scaling symmetries caused by quantum fluctuations. Although they appear prominently in quantum field theory to regularize divergent physical quantities, their influence on experimental observables is difficult to discern. Here, we discovered a striking manifestation of a quantum anomaly in the momentum-space dynamics of a 2D Fermi superfluid of ultracold atoms. We measured the position and pair momentum distribution of the superfluid during a breathing mode cycle for different interaction strengths across the BEC-BCS crossover. Whereas the system exhibits self-similar evolution in the weakly interacting BEC and BCS limits, we found a violation in the strongly interacting regime. The signature of scale-invariance breaking is enhanced in the first-order coherence function. In particular, the power-law exponents that characterize long-range phase correlations in the system are modified due to this effect, indicating that the quantum anomaly has a significant influence on the critical properties of 2D superfluids.

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。

↑