Settembrini Francesca Fabiana, Lindel Frieder, Herter Alexa Marina, Buhmann Stefan Yoshi, Faist Jérôme
ETH Zurich, Institute of Quantum Electronics, Auguste-Piccard-Hof 1, 8093, Zurich, Switzerland.
Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104, Freiburg, Germany.
Nat Commun. 2022 Jun 13;13(1):3383. doi: 10.1038/s41467-022-31081-1.
According to quantum field theory, empty space-the ground state with all real excitations removed-is not empty, but filled with quantum-vacuum fluctuations. Their presence can manifest itself through phenomena such as the Casimir force, spontaneous emission, or dispersion forces. These fluctuating fields possess correlations between space-time points outside the light cone, i.e. points causally disconnected according to special relativity. As a consequence, two initially uncorrelated quantum objects in empty space which are located in causally disconnected space-time regions, and therefore unable to exchange information, can become correlated. Here, we have experimentally demonstrated the existence of correlations of the vacuum fields for non-causally connected space-time points by using electro-optic sampling. This result is obtained by detecting vacuum-induced correlations between two 195 fs laser pulses separated by a time of flight of 470 fs. This work marks a first step in analyzing the space-time structure of vacuum correlations in quantum field theory.
根据量子场论，真空——去除所有真实激发后的基态——并非空无一物，而是充满了量子真空涨落。它们的存在可以通过诸如卡西米尔力、自发辐射或色散力等现象表现出来。这些涨落场在光锥之外的时空点之间存在关联，也就是说，根据狭义相对论，这些点在因果关系上是不相连的。因此，真空中最初不相关的两个量子物体，位于因果关系不相连的时空区域，因此无法交换信息，但它们可以变得相关。在这里，我们通过电光采样实验证明了非因果连接的时空点的真空场关联的存在。这个结果是通过检测两个飞行时间为470飞秒、间隔为195飞秒的激光脉冲之间的真空诱导关联而获得的。这项工作标志着在分析量子场论中真空关联的时空结构方面迈出了第一步。
