Ultrafast visualization of an electric field under the Lorentz transformation
Ultrafast visualization of an electric field under the Lorentz transformation
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DOI：
10.1038/s41567-022-01767-w
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发表时间：
2022-10
期刊：
影响因子：
19.6
通讯作者：
M. Ota;K. Kan;Soichiro Komada;Y. Wang;V. Agulto;V. Mag-usara;Y. Arikawa;M. Asakawa;Y. Sakawa;T. Matsui;M. Nakajima
中科院分区：
文献类型：
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作者：
M. Ota;K. Kan;Soichiro Komada;Y. Wang;V. Agulto;V. Mag-usara;Y. Arikawa;M. Asakawa;Y. Sakawa;T. Matsui;M. Nakajima
在狭义相对论中，四向量，如时空、能量动量和电磁势向量，遵循洛伦兹变换。时空和能量动量矢量的变换分别通过时间膨胀和静止质能实验进行了检验。然而，由于诊断的限制，电磁势的洛伦兹变换从未在实验中直接证明过。在这里，我们展示了通过基于电光采样的太赫兹技术获得的亚皮秒时间分辨率的高能量电子束周围的时空电场分布。我们观察到在洛伦兹变换下，光束在传播方向上的库仑场收缩。当光束穿过金属板后，我们研究了金属板周围库仑场的产生，并跟踪了由limacund - wiechert势导出的球面波前的时空演变。实验证实，在远传播距离测量的电场分布与li<s:1>纳德-维切特势和洛伦兹变换的计算相吻合。我们对时空相对论电场的超快测量不仅为狭义相对论提供了额外的实验证据，而且为高能带电粒子束和电磁辐射物理的详细实验研究提供了平台。
In special relativity, four-vectors, such as space–time, energy–momentum and electromagnetic potential vectors, follow the Lorentz transformation. The transformations of space–time and energy–momentum vectors have been tested by time dilation and rest mass energy experiments, respectively. However, the Lorentz transformation of electromagnetic potentials has never been directly demonstrated in experiments due to the limitations of the diagnostics. Here we show the spatiotemporal electric-field profiles around a highly energetic electron beam with a subpicosecond temporal resolution obtained by a terahertz technique based on electro-optic sampling. We observe the Coulomb field contraction in the propagation direction of the beam under the Lorentz transformation. After passing the beam through a metallic plate, we investigate the birth of the Coulomb field around it and follow the spatiotemporal evolution of the spherical wavefront, which is derived by the Liénard–Wiechert potentials. The measured electric-field profile in the far propagation distance is experimentally confirmed to coincide with the calculation of the Liénard–Wiechert potentials and the Lorentz transformation. Our ultrafast measurement of a spatiotemporal relativistic electric field provides both additional experimental evidence of special relativity and a platform for detailed experimental research of energetic charged particle beams and electromagnetic radiation physics.