Quantum Dots能产生单光子 - 怎么知道是单光子呢？

[TheMatrix]

Researchers control individual light quanta at very high speed

A team of German and Spanish researchers from Valencia, Münster, Augsburg, Berlin and Munich have succeeded in controlling individual light quanta to an extremely high degree of precision. In Nature Communications, the researchers report how, by means of a soundwave, they switch individual photons on a chip back and forth between two outputs at gigahertz frequencies. This method, demonstrated here for the first time, can now be used for acoustic quantum technologies or complex integrated photonic networks.

"Light quanta or photons play a very central role in the development of quantum technologies," says physicist Prof. Hubert Krenner, who heads the study in Münster and Augsburg. "Our team has now succeeded in generating individual photons on a chip the size of a thumbnail and then controlling them with unprecedented precision, precisely clocked by means of soundwaves," he says.

Dr. Mauricio de Lima, who researches at the University of Valencia and coordinates the work being done there, adds, "The functional principle of our chip was known to us as regards conventional laser light, but now, using light quanta, we have succeeded in making the long wished-for breakthrough towards quantum technologies."

In their study, the researchers fabricated a chip which is equipped with minute "conducting paths" for light quanta—so-called waveguides. These are approximately 30 times thinner than a human hair. In addition, this chip contained quantum light sources, so-called quantum dots.

Dr. Matthias Weiß from the University of Münster carried out the optical experiments and adds: "These quantum dots, just a few nanometers in size, are islands inside the waveguides which emit light as individual photons. The quantum dots are included in our chip and so we don't have to use complicated methods to generate individual photons by means of another source."

Dr. Dominik Bühler, who designed the quantum chips as part of his Ph.D. at the University of Valencia, points out how fast the technology is: "By using nanoscale soundwaves, we are able to directly switch the photons on the chip back and forth between two outputs at unprecedented speed during their propagation in the waveguides."

The researchers consider their results to be a milestone on the way towards hybrid quantum technologies as they combine three different quantum systems: quantum light sources in the form of quantum dots, the light quanta created, and phonons (the quantum particles in the soundwave). The hybrid quantum chips—designed at the University of Valencia and manufactured at the Paul Drude Institute of Solid-State Electronics using quantum dots produced at the Technical University of Munich—exceeded the expectations which the research team had.

The international team has taken a further decisive step towards acoustic quantum technologies. "We are already working flat out to enhance our chip so that we can program the quantum state of the photons as we wish, or even control several photons with different colors between four or more outputs," says Dr. Mauricio de Lima, with a view to the future.

Prof. Hubert Krenner adds, "We benefit here from a unique strength which our nanoscale soundwaves have: as these waves propagate virtually loss-free on the surface of the chip, we can neatly control almost as many waveguides as we want with just one single wave—and to an extremely high degree of precision."

More information: Dominik D. Bühler et al, On-chip generation and dynamic piezo-optomechanical rotation of single photons, Nature Communications (2022). DOI: 10.1038/s41467-022-34372-9

Journal information: Nature Communications

[dreamig]

最新骗局

[TheMatrix]

最新骗局

骗人也得说出点道理来。Quantum dots到底怎么产生单光子的呢？怎么确认的呢？

[赖美豪中]

你知道quantum dot是啥意思对么，btw，文章卖点不是单光子，是control and high speed. 单光子从来都不在讨论范围里

骗人也得说出点道理来。Quantum dots到底怎么产生单光子的呢？怎么确认的呢？

[TheMatrix]

你知道quantum dot是啥意思对么

看过介绍，但是没看懂。

[TheMatrix]

这篇短报道的要点不是如何产生单光子，而是用声波控制单光子。

是。早就默认可以产生单光子了。但是怎么确认的呢？

[TheMatrix]

你知道quantum dot是啥意思对么，btw，文章卖点不是单光子，是control and high speed. 单光子从来都不在讨论范围里

是。这说明单光子在一个圈子里已经是共识。但是不明白啊。谁给科普一下？

[赖美豪中]

我知道你是啥意思，但是做quantum dot这批人不会和你讨论哲学问题的

是。这说明单光子在一个圈子里已经是共识。但是不明白啊。谁给科普一下？

[弃婴千枝]

因为只有一个quantum dot,

因为电子是费米子，

一个quantum dot只能有一个电子在激发态，从激发态掉下来只能产生一个photon

这个帖子的重点是，用声表面器件调节quantum dot的高度，从而调节电子能量，从而调节产生的单光子能量

quantum dot单光子emitter是成熟商业产品，花钱就能买到，不是本贴的重点

是。这说明单光子在一个圈子里已经是共识。但是不明白啊。谁给科普一下？

[赖美豪中]

他是要展开哲学讨论，就如何通过探测决定这是一个单光子。然后又开始炒一遍纠缠态，双峰实验，哥本哈根大战爱因斯坦

因为只有一个quantum dot,

因为电子是费米子，

一个quantum dot只能有一个电子在激发态，从激发态掉下来只能产生一个photon

这个帖子的重点是，用声表面器件调节quantum dot的高度，从而调节电子能量，从而调节产生的单光子能量

quantum dot单光子emitter是成熟商业产品，花钱就能买到，不是本贴的重点

[TheMatrix]

因为只有一个quantum dot,

因为电子是费米子，

一个quantum dot只能有一个电子在激发态，从激发态掉下来只能产生一个photon

这个帖子的重点是，用声表面器件调节quantum dot的高度，从而调节电子能量，从而调节产生的单光子能量

quantum dot单光子emitter是成熟商业产品，花钱就能买到，不是本贴的重点

谢谢。我想起来一些，是电子从激发态上下来。

一个Quantum dot只有一个电子处于激发态。一个quantum dot有多大？我想象怎么也得是一团原子，10^5个。怎么就知道只有一个电子处于激发态？

[TheMatrix]

他是要展开哲学讨论，就如何通过探测决定这是一个单光子。然后又开始炒一遍纠缠态，双峰实验，哥本哈根大战爱因斯坦

先别假定太多。

[弃婴千枝]

物理根你的数学不一样，
物理是受许许多多细小的实验事实约束的科学，你必须熟悉这些细枝末节的实验事实，
比如电子是费米子，这点是今天你这个问题的关键
你不把这些细枝末节熟记在心，是没法玩这玩意的
你的问题是对这些细枝末节一无所知

谢谢。我想起来一些，是电子从激发态上下来。

一个Quantum dot只有一个电子处于激发态。一个quantum dot有多大？我想象怎么也得是一团原子，10^5个。怎么就知道只有一个电子处于激发态？

[TheMatrix]

物理根你的数学不一样，
物理是受许许多多细小的实验事实约束的科学，你必须熟悉这些细枝末节的实验事实，
比如电子是费米子，这点是今天你这个问题的关键
你不把这些细枝末节熟记在心，是没法玩这玩意的
你的问题是对这些细枝末节一无所知

电子是费米子这个我知道 - 同一轨道上两个电子自旋相反。

但是一个Quantum dot有多大？就一个原子？

[Caravel]

谢谢。我想起来一些，是电子从激发态上下来。

一个Quantum dot只有一个电子处于激发态。一个quantum dot有多大？我想象怎么也得是一团原子，10^5个。怎么就知道只有一个电子处于激发态？

著名的Coulomb blockade effects

[chuanjianguo]

这种事情耗子就没了身影，只有弃婴

[TheMatrix]

著名的Coulomb blockade effects

好像看懂了。谢谢。

好像的确能控制单电子的流动。。。然后再控制单电子能级跃迁，产生单光子？

[Caravel]

好像看懂了。谢谢。

好像的确能控制单电子的流动。。。然后再控制单电子能级跃迁，产生单光子？

单个量子点，最高能级又是一个电子，看上去是能够实现单光子光源的把。

[TheMatrix]

单个量子点，最高能级又是一个电子，看上去是能够实现单光子光源的把。

这个过程确实能产生不连续的能级，好像可以接受。

[zeami]

这个过程确实能产生不连续的能级，好像可以接受。

晕，本来就是用的乃们的 Perturbation theory