Bentzien Johannes, Pinske Julien, Maczewsky Lukas J, Weimann Steffen, Heinrich Matthias, Scheel Stefan, Szameit Alexander
Institute of Physics, University of Rostock, Albert-Einstein-Str. 23, 18059, Rostock, Germany.
Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100, Copenhagen, Denmark.
Nat Commun. 2025 Sep 5;16(1):8225. doi: 10.1038/s41467-025-63242-3.
The concept of parity-time symmetry has firmly established non-Hermiticity as a versatile degree of freedom on a variety of physical platforms. In general, the non-Hermitian dynamics of open systems are perceived to be inextricably linked to complex-valued potentials facilitating the local attenuation and coherent amplification in wave mechanics. Along these lines, time reversal symmetry is associated with a complex conjugation of the potential landscape, in essence swapping gain and loss. Here we leverage nonorthogonal coupled-mode theory to synthesize genuinely non-Hermitian dynamics without either gain or loss, and experimentally demonstrate parity-time symmetry via fluorescence measurements in femtosecond-laser-written arrays. Our projective approach allows features of non-Hermiticity to be utilized in scenarios where actual amplification and/or attenuation may disrupt the desired physics, e.g. in nonlinear systems or quantum optics.
宇称-时间对称的概念已将非厄米性牢固地确立为各种物理平台上一种通用的自由度。一般来说，开放系统的非厄米动力学被认为与复值势紧密相连，这种势在波动力学中促进了局部衰减和相干放大。沿着这些思路，时间反演对称与势场的复共轭相关联，本质上是交换了增益和损耗。在此，我们利用非正交耦合模理论来合成真正无增益或损耗的非厄米动力学，并通过飞秒激光写入阵列中的荧光测量实验证明了宇称-时间对称。我们的投影方法允许在实际放大和/或衰减可能干扰所需物理过程的场景中利用非厄米性的特征，例如在非线性系统或量子光学中。
