Nocturnal boat ride—MC*
It is not my case that I understand quantum teleportation enough to produce “Quantum Teleportation for Dummies.” I wish I could with the news that Chinese scientists have successfully teleported an object from Earth to a satellite 300 miles above in orbit. The success is attributed to the still mind-numbing idea of quantum entanglement.
I have written about quantum entanglement, one as recently as May 30, 2014 when a team of physicists at the Netherlands’ Kavli Institute of Nanoscience were successfully able to teleport information between two quantum bits separated by 3 meters. Their distance was only 3 meters, which is remarkable as a first step but not very useful in creating actual applications. The one achieved by the Chinese scientists is quite a leap when you consider a distance of 300 miles or 482803 meters.
As part of their experiment they fired photons from Ngari in Tibet to its Micius satellite orbiting Earth at 300 miles. The bit about quantum entanglement came when two photons shared the same quantum state. If that is too much for you to crack it, it is because it is too much to crack for most people. Let me compound it by quoting from the extract of the scientists’ paper published online on arXiv.
It says, “An arbitrary unknown quantum state cannot be precisely measured or perfectly replicated. However, quantum teleportation allows faithful transfer of unknown quantum states from one object to another over long distance, without physical travelling of the object itself. Long-distance teleportation has been recognized as a fundamental element in protocols such as large-scale quantum networks and distributed quantum computation. However, the previous teleportation experiments between distant locations were limited to a distance on the order of 100 kilometers, due to photon loss in optical fibres or terrestrial free-space channels. An outstanding open challenge for a global-scale "quantum internet" is to significantly extend the range for teleportation. A promising solution to this problem is exploiting satellite platform and space-based link, which can conveniently connect two remote points on the Earth with greatly reduced channel loss because most of the photons' propagation path is in empty space. Here, we report the first quantum teleportation of independent single-photon qubits from a ground observatory to a low Earth orbit satellite - through an up-link channel - with a distance up to 1400 km. To optimize the link efficiency and overcome the atmospheric turbulence in the up-link, a series of techniques are developed, including a compact ultra-bright source of multi-photon entanglement, narrow beam divergence, high-bandwidth and high-accuracy acquiring, pointing, and tracking (APT). We demonstrate successful quantum teleportation for six input states in mutually unbiased bases with an average fidelity of 0.80+/-0.01, well above the classical limit. This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet.”
In order to make it a little more palatable, I am reproducing what I wrote some three years ago after the first successful teleportation of information over three meters.
Trying to make sense out of quantum entanglement in the midst of a migraine attack is nearly lethal. However, it seems to me that the only way to understand quantum entanglement is via a migraine attack. Having lived with migraines of varying ferocity for almost my entire life, I can now conclude that they give you such dazzling clarity about concepts of physics as is not possible in a normal state.
I am thinking of quantum entanglement this morning because it is being reported that a team of physicists at the Netherlands’ Kavli Institute of Nanoscience has been successfully able to teleport information between two quantum bits separated by 3 meters. As I mentioned, I would not have been able to comprehend any of this in a normal state without a migraine attack. Since I am going through one right now I am able to make much better sense of this finding for myself than I normally would have. Think of migraine as a lens that sharpens the information that goes through it. I call it migraine lensing. Unfortunately, I don’t think I can explain to you what stands fully explained to me right now.
Teleportation is an idea familiar to us as part of ‘Star Trek’ folklore and other science fiction stories. What the Kavli scientists are reporting is not about teleporting actual people such as Captain James Tiberius Kirk or Mr. Spock (I am being ironic by calling them actual people). It is about teleporting information between two points, which would constitute the fundamentals of the much talked about quantum computing. From Isaac Newton’s precisely deterministic universe to Albert Einstein’s more subtle and nuanced universe to rather bizarrely unpredictable quantum universe there are several layers of the physics of our universe. Just as Newton might have found weird and bizarre Einstein’s assertion that there is no single universal clock or time or what is now here is something else a billion light years away, Einstein found the quantum world equally weird and bizarre. Responding to the idea of quantum mechanics he famously said, "physics should represent a reality in time and space, free from spooky actions at a distance." The idea that two particles separated by a massive, unimaginable distance can affect each other or in a way are entangled as memorably described by Erwin Schrodinger, for want of a better expression, freaked Einstein out. You should bear in mind is that Einstein’s freaking out is not like an ordinary mortal’s freaking out. It is based on some profound objections. Unraveling Einstein’s freaking out can earn you a PhD in physics.
So far computing is in the realm of classical bits, meaning information getting transferred in the two values of 0 and 1. Quantum computing, in contrast, allows for information to be transferred in many different values through what is known as quantum bits or qubits. Quantum computing is supposed to be way more reliable than classical computing, the way it is done now.It is in this context that what the Kavli scientists are reporting is extraordinary. They say they have been able to teleport information absolutely accurately, meaning without losing any data. From the 3 meter transfer, they now propose to do it over a distance of over one kilometer and eventually over longer distances. This is their way of showing that quantum entanglement works, something that completely defies Einstein’s idea of what he called “spooky actions at a distance.”
The above description was written by me in a span of about ten minutes under the dazzling clarity created by my migraine attack. As it begins to wear off because of a pain killer and as I return to my normal state, that comprehension is beginning to fade. So I might as well end it here. If you do not understand what I have said here, well it is just too bad. Not everything is for everyone. Either that or go get a migraine.
I am fairly certain that did not make it any easier because it did not make it easier for me either even though I was the one who wrote it. Suffice it to know that it works and will absolutely revolutionize the way we transfer information or communicate. One of the key features of quantum computing would be that it cannot be tapped into or broken into without the user instantly finding out that it is being broken into. The thing with eavesdropping on quantum particles such as photons is that the act of observing creates disturbance in them. It alters their state.
* My latest painting has nothing to do with the theme of the post except that it looks mysterious. Also, it gives me an excuse to plug it here.