Group items tagged

Travelling through wormholes is not much different from quantum teleportation using entangled black holes...

Blockchains, now with more buzzwords!

Time travel! Finally. Can we also use it for antigravity?

Related paper at: http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.118.080501

maybe also a future way to store information?

Can some of our quantum experts elaborate a bit on implications etc.? :) I'm not sure I follow.

Doesn't really sound sexy, but this is of utmost importance for next generation grids for renewable energy.

I agree on the significance indeed - a small boost also for my favourite Desertec project ... Though their language is a bit too "grandiose": "ABB has successfully designed and developed a hybrid DC breaker after years of research, functional testing and simulation in the R&D laboratories. This breaker is a breakthrough that solves a technical challenge that has been unresolved for over a hundred years and was perhaps one the main influencers in the 'war of currents' outcome. The 'hybrid' breaker combines mechanical and power electronics switching that enables it to interrupt power flows equivalent to the output of a nuclear power station within 5 milliseconds - that's as fast as a honey bee takes per flap of its wing - and more than 30 times faster than the reaction time of an Olympic 100-meter medalist to react to the starter's gun! But its not just about speed. The challenge was to do it 'ultra-fast' with minimal operational losses and this has been achieved by combining advanced ultrafast mechanical actuators with our inhouse semiconductor IGBT valve technologies or power electronics (watch video: Hybrid HVDC Breaker - How does it work). In terms of significance, this breaker is a 'game changer'. It removes a significant stumbling block in the development of HVDC transmission grids where planning can start now. These grids will enable interconnection and load balancing between HVDC power superhighways integrating renewables and transporting bulk power across long distances with minimal losses. DC grids will enable sharing of resources like lines and converter stations that provides reliability and redundancy in a power network in an economically viable manner with minimal losses. ABB's new Hybrid HVDC breaker, in simple terms will enable the transmission system to maintain power flow even if there is a fault on one of the lines. This is a major achievement for the global R&D team in ABB who have worked for years on the challeng

An excellent science coffee topic! This is a true breakthrough in pure mathematics with plentiful applications in the lesser sciences (such as theoretical physics). People tell me quantum gravity is already practically solved by this. Conway's powerful theory of Alternative Facts can render many difficult problems tractable. Here we demonstrate the power of AF to prove the Riemann Hypothesis, one of the most important unsolved problems in mathematics. We further suggest applications of AF to other challenging unsolved problems such as the zero-equals-one conjecture (which is also true) and the side-counting problem of the circle.

Sorry ,here now the right link to the nature paper ...in english

Zeilinger strikes again ...

I like this one "The kind of idle pastime that might amuse physicists is to imagine drafting Einstein's grant applications in 1905. "I propose to investigate the idea that light travels in little bits," one might say. "I will explore the possibility that time slows down as things speed up," goes another. Imagine what comments these would have elicited from reviewers for the German Science Funding Agency, had such a thing existed. Instead, Einstein just did the work anyway while drawing his wages as a technical expert third-class at the Bern patent office. And that is how he invented quantum physics and relativity." There is an even more pointer example of the Prussian academy of sciences reviewing the Dr. application of Hertz ...

Shocking. What is federal research funding for? No, wrong question. Instead maybe: What is federally funded review for?

For all the AI guys (Christos, Marek, Ed, Markus and co ...) and of course Luiz, Sante ... You will like this one :-)

Quite a lot of blabla, some usual misconceptions (like QT the source of randomness in nature), but a -- from my point of view -- very true (though in the text somehow hidden) conclusion: Free will, creativity etc. from the point of view of fundamental physics are just randomness! Many physicists won't like this conclusion, though, and in this respect also the title is rather misleading!

The ability to teleport energy from one location to another could revolutionise the way quantum devices operate, but only if it can be made to work over practical distances. Now physicists think they know how.

"When a control laser is fired at the crystal, a complex quantum-level reaction turns it the opaque crystal transparent. A second light source is beamed into the crystal before the control laser is shut off, returning the crystal to its opaque state. This leaves the light trapped inside the crystal, and the opacity of the crystal keeps the light trapped inside from bouncing around, effectively bringing light to a full stop." is the simple explanation, but I am not sure how this is actually possible with the current laws of physics

There are two ways to make slow light: material slow light and structural slow light, where you either change the material or the structural properties of your system. Here they used EIT to make material slow light, by inducing transparency inside an otherwise opaque material. As you change the absorption properties of a material you also change its dispersion properties, the so-called Kramers-Kronig relations. A rapid positive change in the dispersion properties of a material will give rise to slow light. To effectively stop light they switched off the control beam, bringing back the opaque state. Another control beam is then used to retrieve the probe pulse that was 'frozen' inside the medium. Light will be halted according to the population lifetime on the energy level (~ 100s). They used an evolutionary algorithm to find an optimal pulse preparation sequence to reach close to the maximum possible storage duration of 100s. Interesting paper!

So it is not real storage then in a sense, as you are stimulating an excitation population which retains the phase information of your original pulse? Still it is amazing that they could store this up to 100s and retrieve it with a probe pulse, but light has never been halted.

Looks fantastic!

Sounds like a great tool for calculation and may provide some deeper understanding. But: I think their comments about space and time are misleading. Often you can ignore space and time when you just want the probability of an event (and it makes your calculations easier) but especially in the low-energy regime an event is clearly localized.

where is Luzi? where is Anna? where is Sante? when you need them?

The first "molecules" made from two photons have been created by physicists in the US. The breakthrough could allow both conventional and quantum computers to encode and process information using photons.

I wonder if the effect also works with much larger numbers of photons involved. By slowing down any initial (Rydberg) photons and letting the later photons catch up it might be possible to create a very sharp "shock" front of photons. This could produce in itself be an ultra-short pulse of light or maybe it could be used as the trigger for massive stimulated emission in a laser.