Parity-time-symmetric quantum critical phenomena.
Parity-time-symmetric quantum critical phenomena.
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DOI：
10.1038/ncomms15791
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发表时间：
2017-06-08
影响因子：
16.6
通讯作者：
Ueda M
中科院分区：
文献类型：
--
作者：
Ashida Y;Furukawa S;Ueda M
具有宇称-时间（PT）对称的增益 - 损耗结构的合成非保守系统能够展现出伴随光谱奇异性的异常自发对称破缺。近期在光学和弱相互作用开放量子系统中对PT对称性的研究揭示了一些有趣的物理性质，但多体关联仍然不起作用。在此，通过将PT对称性的概念扩展到强关联多体系统，我们报道光谱奇异性和量子临界性的结合产生了一种奇异的普适类，它在已知的临界现象中没有对应物。此外，我们发现了非常规的低维量子临界性，在PT对称破缺的量子临界相中，由于非单调的重整化群流，超流关联异常增强，这与别列津斯基 - 科斯特利茨 - 索利斯范式形成鲜明对比。我们的发现可以在超冷原子中进行实验验证，并预测超出量子多体物理厄米范式的临界现象。
宇称 - 时间（PT）对称性主要在没有多体关联的光学和弱相互作用开放量子系统中被研究。在此作者表明，在一个强关联多体系统中，关联和PT对称性之间的相互作用导致了新的临界现象的出现。
Synthetic non-conservative systems with parity-time (PT) symmetric gain–loss structures can exhibit unusual spontaneous symmetry breaking that accompanies spectral singularity. Recent studies on PT symmetry in optics and weakly interacting open quantum systems have revealed intriguing physical properties, yet many-body correlations still play no role. Here by extending the idea of PT symmetry to strongly correlated many-body systems, we report that a combination of spectral singularity and quantum criticality yields an exotic universality class which has no counterpart in known critical phenomena. Moreover, we find unconventional low-dimensional quantum criticality, where superfluid correlation is anomalously enhanced owing to non-monotonic renormalization group flows in a PT-symmetry-broken quantum critical phase, in stark contrast to the Berezinskii–Kosterlitz–Thouless paradigm. Our findings can be experimentally tested in ultracold atoms and predict critical phenomena beyond the Hermitian paradigm of quantum many-body physics. Parity-time (PT) symmetry has been mainly studied in optical and weakly interacting open quantum systems without many-body correlations. Here the authors show that in a strongly correlated many-body system the interplay between correlations and PT symmetry leads to the emergence of new critical phenomena.