1.媒体来源: Phys.org
2.完整新闻标题:
Physicists detect exotic looped trajectories of light in three-slit experiment
物理学家从三狭缝实验中发现 奇异弯曲的光轨迹
3.完整新闻内文:
January 6, 2017 by Lisa Zyga
http://imgur.com/88NumP2.jpg
The red path shows an exotic looped trajectory of light through a three-slit
structure, which was observed for the first time in the new study. Credit:
Magaña-Loaiza et al. Nature Communications
图中的红线显示出，奇异弯曲的光轨迹穿过三狭缝结构，这是第一次从实验中观测到这种
现象。来源: Magaña-Loaiza et al. Nature Communications
(Phys.org)—Physicists have performed a variation of the famous 200-year-old
double-slit experiment that, for the first time, involves "exotic looped
trajectories" of photons. These photons travel forward through one slit, then
loop around and travel back through another slit, and then sometimes loop
around again and travel forward through a third slit.
(Phys.org)—物理学家已经演示了著名的且有200年历史的双狭缝实验，但这是第一次涉
及光子的"奇异弯曲轨迹"。这些光子穿过第一道狭缝后，转弯倒车穿过第二道狭缝，然后
再转弯回正穿过第三道狭缝。
Interestingly, the contribution of these looped trajectories to the overall
interference pattern leads to an apparent deviation from the usual form of
the superposition principle. This apparent deviation can be understood as an
incorrect application of the superposition principle—once the additional
interference between looped and straight trajectories is accounted for, the
superposition can be correctly applied.
有趣的是，这些弯曲轨迹，对总干涉图形的贡献，与叠加原理的常见形式比较，有明显的
误差。该明显误差可以理解为不正确地使用叠加原理 - 一旦考虑了弯曲和直线轨迹之间
的附加干扰，则可以正确地应用叠加原理。
The team of physicists, led by Omar S. Magaña-Loaiza and Israel De Leon, has
published a paper on the new experiment in a recent issue of Nature
Communications.
由 Omar S.Magaña-Loaiza 与以色列 De Leon 领导的物理学家团队，在最近一期的
Nature Communications 上，发表了一篇关于新实验的论文。
Loops of light
弯曲的光
"Our work is the first experimental observation of looped trajectories," De
Leon told Phys.org. "Looped trajectories are extremely difficult to detect
because of their low probability of occurrence. Previously, researchers had
suggested that these exotic trajectories could exist but failed to observe
them."
De Leon 向 Phys.org 表示，"我们的成果是第一个从实验中观察到弯曲轨迹"。"弯曲轨
迹极难探测，因为它们发生的机率很低。在过去，研究者曾提出这些奇异的轨迹可能存在
，但未能观察到它们。"
To increase the probability of the occurrence of looped trajectories, the
researchers designed a three-slit structure that supports surface plasmons,
which the scientists describe as "strongly confined electromagnetic fields
that can exist at the surface of metals." The presence of these
electromagnetic fields near the three slits increases the contribution of
looped trajectories to the overall interference pattern by almost two orders
of magnitude.
为了增加弯曲轨迹发生的机率，研究者设计了提供表面电浆子的三狭缝结构，科学家将其
描述为"可存在于金属表面的强限制电磁场"。在三狭缝附近的电磁场，增加了弯曲轨迹对
整体干涉图形的贡献，几乎两个数量级。
"We provided a physical explanation that links the probability of these
exotic trajectories to the near fields around the slits," De Leon said. "As
such, one can increase the strength of near fields around the slits to
increase the probability of photons following looped trajectories."
De Leon 表示"我们提供了一个物理解释，将这些奇异轨迹的机率连系到狭缝周围的近场
。因此，增加狭缝周围近场的强度，可以增加光子走弯曲轨迹的机率。"
Superposition principle accounting for looped trajectories
考虑弯曲轨迹的叠加原理
The new three-slit experiment with looped trajectories is just one of many
variations of the original double-slit experiment, first performed by Thomas
Young in 1801. Since then, researchers have been performing versions that use
electrons, atoms, or molecules instead of photons.
有弯曲轨迹的新三狭缝实验，是原始双狭缝实验的许多变种之一。最初的双狭缝实验由
Thomas Young 在1801年进行。从那时起，研究人员一直在使用电子, 原子或分子代替光
子。
One of the reasons why the double-slit experiment has attracted so much
attention is that it represents a physical manifestation of the principle of
quantum superposition. The observation that individual particles can create
an interference pattern implies that the particles must travel through both
slits at the same time. This ability to occupy two places, or states, at
once, is the defining feature of quantum superposition.
双狭缝实验引起了这么多关注的原因之一是，它证明了量子叠加原理。各别的粒子可以产
生干涉图形的观察结果，意味着粒子必须同时穿过两个狭缝。这种同时占据两个地方或状
态的能力是量子叠加的特征。
http://imgur.com/4wEv3Z6.jpg
Straight trajectories (green) and exotic looped trajectories (red, dashed,
dotted) of light, where the red cloud near the surface depicts the near
fields, which increase the probability of photons to follow looped
trajectories. The graphs at left show simulations (top) and experimental
results (bottom) of the large difference in interference patterns created by
illuminating only one slit being treated independently (gray line) and the
actual coupled system (blue line). The remarkable difference between the gray
and blue lines is caused by the looped trajectories. Credit: Magaña-Loaiza
et al. Nature Communications
光的直线轨迹(绿色)和奇异弯曲轨迹(红色, 虚线, 虚线)。其中表面附近的红云描绘了近
场，这增加了光子走弯曲轨迹的机率。右侧的图为模拟(上)与实验(下)的干涉图形，显示
了单独处理照射一个狭缝(灰线)与实际耦合系统(蓝线)的巨大差异。灰线和蓝线之间的显
著差异是由弯曲轨迹造成的。来源: Magaña-Loaiza et al. Nature Communications
So far, all previous versions of the experiment have produced results that
appear to be accurately described by the principle of superposition. This is
because looped trajectories are so rare under normal conditions that their
contribution to the overall interference pattern is typically negligible, and
so applying the superposition principle to those cases results in a very good
approximation.
迄今为止，所有先前版本的实验，可以用叠加原理精确地描述实验结果。这是因为在正常
条件下，弯曲轨迹是非常罕见的，使得它们对整体干涉图形的贡献通常可忽略，并且可用
叠加原理去解释那些情况。
It is when the contribution of the looped trajectories becomes non-negligible
that it becomes apparent that the total interference is not simply the
superposition of individual wavefunctions of photons with straight
trajectories, and so the interference pattern is not correctly described by
the usual form of the superposition principle.
当弯曲轨迹的贡献变得不可忽略时，很明显地，总干涉图形不是由各别的直线轨迹光子的
波函数叠加，因此干涉图形不能以叠加原理的通常形式来解释。
Magaña-Loaiza explained this apparent deviation in more detail:
Magaña-Loaiza 更详细地解释了这种明显的误差:
"The superposition principle is always valid—what is not valid is the
inaccurate application of the superposition principle to a system with two or
three slits," he said.
他表示: "叠加原理一直是正确的，不正确的是，错误的使用叠加原理在两个或三个狭缝
系统"。
"For the past two centuries, scientists have assumed that one cannot observe
interference if only one slit is illuminated in a two- or three-slit
interferometer, and this is because this scenario represents the usual or
typical case.
在过去的两个世纪里，科学家们认为，如果在双或三狭缝干涉仪中，只有一个狭缝被照射
，那么人们不能观察到干涉，这是因为这种情况代表了通常或典型的情况。
"However, in our paper we demonstrate that this is true only if the
probability of photons to follow looped trajectories is negligible.
Surprisingly, interference fringes are formed when photons following looped
trajectories interfere with photons following straight (direct) trajectories,
even when only one of the three slits is illuminated.
"然而，在我们的论文中，我们证明只有当光子走弯曲轨迹的机率可忽略时，这种情况才
是对的。出乎意料的是，即使三个狭缝中只有一个被照射，走弯曲轨迹的光子会干涉走直
线轨迹的光子，形成干涉条纹。"
"The superposition principle can be applied to this surprising scenario by
using the sum or 'superposition' of two wavefunctions; one describing a
straight trajectory and the other describing looped trajectories. Not taking
into account looped trajectories would represent an incorrect application of
the superposition principle.
"叠加原理可以解释这种令人惊奇的情况，透过使用两个波函数的和或'叠加'; 一个波函
数描述直线轨迹的光子，另一个描述弯曲轨迹的。不考虑弯曲轨迹会使叠加原理失效。"
"To some extent, this effect is strange because scientists know that Thomas
Young observed interference when he illuminated both slits and not only one.
This is true only if the probability of photons following looped trajectories
is negligible."
"在某种程度上，这种结果是很奇怪的，因为科学家知道 Thomas Young 是照射两个狭缝
，才观察到干涉，而不是一个。但是这只在弯曲轨迹光子的机率可以忽略时，才是对的。
"
In addition to impacting physicists' understanding of the superposition
principle as it is applied to these experiments, the results also reveal new
properties of light that could have applications for quantum simulators and
other technologies that rely on interference effects.
除了影响物理学家用叠加原理解释这些实验，其结果还揭示了光的新性质，该性质可能用
于量子模拟器与其它使用干涉效应的技术。
"We believe that exotic looped paths can have important implications in the
study of decoherence mechanisms in interferometry or to increase the
complexity of certain protocols for quantum random walks, quantum simulators,
and other algorithms used in quantum computation," De Leon said.
De Leon 表示，"我们认为奇异弯曲路径可能在干涉测量的去相干机制研究中具有重要的
意义，或是增加一些已知方法的复杂度，像是量子随机漫步, 量子模拟器, 和用于量子计
算的其他算法"。
4.完整新闻连结 (或短网址):
https://goo.gl/lEkPLA
5.备注:
原始论文
Exotic looped trajectories of photons in three-slit interference
http://www.nature.com/articles/ncomms13987
叠加原理 - 维基百科，自由的百科全书
https://zh.wikipedia.org/zh-tw/%E5%8F%A0%E5%8A%A0%E5%8E%9F%E7%90%86
态叠加原理 - 维基百科，自由的百科全书
https://zh.wikipedia.org/wiki/%E6%80%81%E5%8F%A0%E5%8A%A0%E5%8E%9F%E7%90%86