Hawking Radiation in Dielectric Horizon Analogues

电介质视界类似物中的霍金辐射

• 批准号: EP/J00443X/1
• 负责人: Daniele Faccio
• 金额: $ 53.85万
• 依托单位: Heriot-Watt University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FJ00443X%2F1
• 关键词: Hawking; Radiation; Dielectric; Horizon; Analogues

Black holes are incredibly fascinating objects. They largely populate the Universe we live in, attracting whole galaxies around them. They also attract the imagination of novel writers and scientists alike: they represent the ultimate frontier at which our knowledge and intellect can be put to the test. In 1974 Stephen Hawking, building upon suggestions that black holes have a finite temperature, predicted that the event horizon surrounding a black hole separates regions characterized by such an intense space-time distortion that photons and particles are literally ripped out of vacuum state. These photons are then seen from outside the black hole to be emitted as a continuous flux of radiation. Black holes glow, just as if they were light bulbs. Unfortunately, this truly amazing prediction has little hope of being verified directly from astrophysical black holes. The "glow" has an extremely low temperature, of the order of tens of nano-Kelvins and cannot be distinguished amongst the much higher cosmic background temperature.Fortunately, exactly 30 years ago, William Unruh noted that the same arguments that lead to black hole evaporation also predict that a thermal spectrum of sound waves should be given out from a flowing fluid whose velocity is made to vary from sub-sonic to super-sonic velocities. Sound waves will remain blocked at the transition between the sub- and super-sonic regions at what, to all effects, is the analogue of an horizon. It now turns out that horizons are apparently far more common than one may imagine. They appear in flowing tap water as it hits the sink and in a number of water or liquid based scenarios; they appear in flowing Bose-Einstein-Condensates, in polariton condensates and, most importantly for what concerns this project, in moving dielectric media. We may imagine moving a transparent glass sample at velocities close to that of light. We would then have a situation analogous to that of sound waves in a moving fluid: in the presence of a transition from sub-luminal to super-luminal speeds, light waves will not be able to move beyond the horizon point at which the medium velocity is exactly equal to the phase velocity of light. One of the PIs (U. Leonhardt) recently proposed an ingenious method to achieve such horizons in a very simple manner. An intense laser pulse propagating in glass will create a local perturbation in the refractive index that travels together with the pulse, i.e. it naturally travels at light speeds. Any light wave approaching the perturbation will be slowed down by the local increase in refractive index and will eventually be blocked at the horizon beyond which it will be never be able to propagate. Using this very simple proposal, the other project PI (D. Faccio) obtained the first evidence of spontaneous photon emission induced by the dielectric horizon. The perturbation is glowing and evaporating by shedding photons excited from the vacuum state, just as Hawking predicted black holes should do. This project aims at taking forth these results and taking studies on Hawking emission and horizon related effects to the next level. We are now able to plan real experiments that can give us for the first time real data describing how horizons interact with the quantum vacuum. Moreover, at the heart of Hawking emission lies a novel amplification mechanism that, due to the lack of any previous experimental possibilities, has never been truly investigated before. This new amplification channel will be studied and used to amplify light. The goal in mind is to create the first black hole laser in which light is trapped in between two separate horizons. Bouncing back and forth it is amplified at each rebound and finally exponentially explodes in laser-like amplification process. The impact of this project therefore goes well beyond investigation of Hawking effects and invests a number of fields, ranging from quantum field theories to nonlinear optics and photonic technologies.

黑洞是令人难以置信的引人入胜的物体。它们在很大程度上遍布我们所生活的宇宙，吸引了周围的整个星系。它们还吸引了新颖作家和科学家的想象力：它们代表了我们的知识和智力可以接受测试的最终边界。 1974年，斯蒂芬·霍金（Stephen Hawking）基于建议黑洞的温度有限的建议，预测围绕黑洞的事件范围将其特征在于这种强烈的时空变形，以至于光子和颗粒实际上是从真空状态中剥离的。然后从黑洞外看到这些光子，以作为辐射的连续通量发出。黑洞发光，就像它们是灯泡一样。不幸的是，这个真正令人惊奇的预测几乎没有希望直接从天体物理黑洞中验证的希望。 The "glow" has an extremely low temperature, of the order of tens of nano-Kelvins and cannot be distinguished amongst the much higher cosmic background temperature.Fortunately, exactly 30 years ago, William Unruh noted that the same arguments that lead to black hole evaporation also predict that a thermal spectrum of sound waves should be given out from a flowing fluid whose velocity is made to vary from sub-sonic to super-sonic velocities.在子和超声区域之间的过渡时，声波将保持阻塞，而所有效果是地平线的类似物。现在事实证明，视野显然比人们想象的要普遍得多。它们出现在流动的自来水中，当它撞到水槽和许多基于水或液体的场景中。它们出现在流动的Bose-Einstein-Condementates中，在北极凝结物中，最重要的是，对于该项目的介绍介质而言，它们最重要。我们可能会想象以接近光的速度移动透明的玻璃样品。然后，我们的情况类似于移动流体中的声波：在存在从亚延伸速度到超亮速速度的过渡时，光波将无法超出中等速度完全等于光相位速度的地平线。 PIS（U. Leonhardt）最近提出了一种巧妙的方法，以非常简单的方式实现这种视野。在玻璃中传播的强激光脉冲将在折射率中产生局部扰动，该指数与脉冲一起传播，即它自然地以光速行驶。任何接近扰动的光波都将因折射率的局部增加而减慢，并最终将在地平线上阻塞，它将永远无法传播。使用这个非常简单的提案，另一个Project PI（D。FACCIO）获得了介电范围诱导的自发光子发射的第一个证据。扰动通过从真空状态激发的光子脱落的光子发光和蒸发，就像霍金预测的黑洞应该做的那样。该项目旨在提出这些结果，并将研究霍金排放和地平线相关的效果研究到一个新的水平。现在，我们能够计划实验，这些实验可以首次为我们提供描述地平线如何与量子真空相互作用的真实数据。此外，霍金发射的核心是一种新颖的放大机制，由于缺乏以前的实验可能性，从未真正研究过。该新的放大通道将被研究并用于放大光。想到的目标是创建第一个黑洞激光器，其中光被困在两个单独的视野之间。来回弹跳，它在每个篮板上都会放大，最后在类似激光的放大过程中呈指数式爆炸。因此，该项目的影响远远超出了对霍金效应的调查，并投资了许多领域，从量子场理论到非线性光学和光子技术。

项目成果

Imaging of polarization-sensitive metasurfaces with quantum entanglement

• DOI: 10.1103/physreva.99.020101
• 发表时间: 2019-02-07
• 期刊: PHYSICAL REVIEW A
• 影响因子: 2.9
• 作者: Altuzarra, Charles;Lyons, Ashley;Faccio, Daniele
• 通讯作者: Faccio, Daniele

Terahertz control of air lasing

• DOI: 10.1103/physreva.99.053802
• 发表时间: 2019-05
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: M. Clerici;A. Bruhacs;D. Faccio;M. Peccianti;M. Spanner;A. Markov;B. Schmidt;T. Ozaki;F. Légaré-F.-Lé

Gravitational parameter estimation in a waveguide

• DOI: 10.1103/physrevd.90.024022
• 发表时间: 2014-07-08
• 期刊: PHYSICAL REVIEW D
• 影响因子: 5
• 作者: Doukas, Jason;Westwood, Luke;Fuentes, Ivette
• 通讯作者: Fuentes, Ivette

Spectrally resolved wave-mixing between near- and far-infrared pulses in gas

• DOI: 10.1088/1367-2630/15/12/125011
• 发表时间: 2013-12-09
• 期刊: NEW JOURNAL OF PHYSICS
• 影响因子: 3.3
• 作者: Clerici, M.;Faccio, D.;Morandotti, R.
• 通讯作者: Morandotti, R.

Interaction between optical fields and their conjugates in nonlinear media.

• DOI: 10.1364/oe.21.031239
• 发表时间: 2013-12
• 期刊: Optics express
• 影响因子: 3.8
• 作者: M. Conforti;A. Marini;Truong X. Tran;D. Faccio;F. Biancalana