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LeopoldS

Operation Socialist: How GCHQ Spies Hacked Belgium's Largest Telco - 4 views

firstlook.org/...elgacom-hack-gchq-inside-story

IT security hacking safety networks

shared by LeopoldS on 16 Dec 14 - No Cached
  • LeopoldS on 16 Dec 14
     
    interesting story with many juicy details on how they proceed ... (similarly interesting nickname for the "operation" chosen by our british friends) "The spies used the IP addresses they had associated with the engineers as search terms to sift through their surveillance troves, and were quickly able to find what they needed to confirm the employees' identities and target them individually with malware. The confirmation came in the form of Google, Yahoo, and LinkedIn "cookies," tiny unique files that are automatically placed on computers to identify and sometimes track people browsing the Internet, often for advertising purposes. GCHQ maintains a huge repository named MUTANT BROTH that stores billions of these intercepted cookies, which it uses to correlate with IP addresses to determine the identity of a person. GCHQ refers to cookies internally as "target detection identifiers." Top-secret GCHQ documents name three male Belgacom engineers who were identified as targets to attack. The Intercept has confirmed the identities of the men, and contacted each of them prior to the publication of this story; all three declined comment and requested that their identities not be disclosed. GCHQ monitored the browsing habits of the engineers, and geared up to enter the most important and sensitive phase of the secret operation. The agency planned to perform a so-called "Quantum Insert" attack, which involves redirecting people targeted for surveillance to a malicious website that infects their computers with malware at a lightning pace. In this case, the documents indicate that GCHQ set up a malicious page that looked like LinkedIn to trick the Belgacom engineers. (The NSA also uses Quantum Inserts to target people, as The Intercept has previously reported.) A GCHQ document reviewing operations conducted between January and March 2011 noted that the hack on Belgacom was successful, and stated that the agency had obtained access to the company's
  • Paul N on 19 Dec 14
     
    I knew I wasn't using TOR often enough...
  • Ma Ru on 24 Dec 14
     
    Cool! It seems that after all it is best to restrict employees' internet access only to work-critical areas... @Paul TOR works on network level, so it would not help here much as cookies (application level) were exploited.
jaihobah

Quantum Computing Test Offers Boost to Quantum Cryptography - 1 views

www.quantamagazine.org/ever-be-able-to-solve-20180621

Comp.Sci. INF

shared by jaihobah on 22 Jun 18 - No Cached
  • jaihobah on 22 Jun 18
     
    Computer scientists have been searching for years for a type of problem that a quantum computer can solve but that any possible future classical computer cannot. Now they've found one.
  • Marcus Maertens on 25 Jun 18
     
    Oh this is a big one! Unfortunately, the problem is only relativized (i.e. you need an oracle for it) but nevertheless an impressive result.
jmlloren

Unsupervised Generative Modeling Using Matrix Product States - 2 views

journals.aps.org/...PhysRevX.8.031012

shared by jmlloren on 18 Jul 18 - No Cached
  • jmlloren on 18 Jul 18
     
    Our work sheds light on many interesting directions of future exploration in the development of quantum-inspired algorithms for unsupervised machine learning, which are promisingly possible to realize on quantum devices.
LeopoldS

new 24qbits quantum computer - 0 views

journals.aps.org/...PRXQuantum.2.020343

quantum

shared by LeopoldS on 18 Jun 21 - No Cached
  • LeopoldS on 18 Jun 21
     
    new 24qbits quantum computer fitting in standard racks ...
santecarloni

How to Measure Quantum Foam With a Tabletop Experiment | MIT Technology Review - 1 views

www.technologyreview.com/...oam-with-a-tabletop-experiment

technology quantum experiment PHY

shared by santecarloni on 20 Nov 12 - No Cached
  • johannessimon81 on 22 Nov 12
     
    I think there are a few difficulties when assuming that the macroscopic block of glass will accelerate instantaneously. Also, if I prevent the block from moving would it become perfectly reflective as no momentum can be transferred to it? One could say that the momentum is then transferred to the larger system that holds the glass. But surely I could make that system (or even the block of glass) so heavy that it would not move more than Planck's length during the passage of the photon - especially if the glass is very thin or the light is very red.
jaihobah

The Long-Awaited Promise of a Programmable Quantum Computer - 0 views

www.technologyreview.com/...-programmable-quantum-computer

quantum computer PHY

shared by jaihobah on 23 Mar 16 - No Cached
  • jaihobah on 23 Mar 16
     
    Scalability claimed but not demonstrated
jcunha

Superfast light source made from artificial atom - 0 views

phys.org/...st-source-artificial-atom.html

technology quantum single photon light dot

shared by jcunha on 02 May 16 - No Cached
  • jcunha on 02 May 16
     
    A new more efficient type of single photon light source consisting of a quantum dot reproduces 1954 Robert Dicke theoretical proposal. Applications in quantum communications directly on the target. "All light sources work by absorbing energy - for example, from an electric current - and emit energy as light. But the energy can also be lost as heat and it is therefore important that the light sources emit the light as quickly as possible, before the energy is lost as heat."
LeopoldS

Phys. Rev. Lett. 108, 153605 (2012): Monolithic Source of Photon Pairs - 0 views

prl.aps.org/...e153605

physics quantum Entanglement

shared by LeopoldS on 18 Apr 12 - No Cached
  • LeopoldS on 18 Apr 12
     
    This is the first time that significant pair production has been demonstrated in a structure that can be electrically self-pumped and which can form the basis for passive optical circuitry, bringing us markedly closer to complete integration of quantum optical technologies.
santecarloni

More evidence found for quantum physics in photosynthesis - 3 views

arstechnica.com/...-physics-in-photosynthesis.ars

quantum physics photosynthesis BIO science

shared by santecarloni on 08 Dec 11 - No Cached
  • LeopoldS on 11 Dec 11
     
    see papers I have just sent you this afternoon ...
jmlloren

QuTiP - Quantum Toolbox in Python - 1 views

qutip.org

NAN PHY INF

shared by jmlloren on 10 Sep 13 - No Cached
H H liked it
  • jmlloren on 10 Sep 13
     
    It is a very interesting projecto to easily perform quantum optics calculations.
Beniamino Abis

Quantum Physics and Game Theory - 1 views

www.bristol.ac.uk/...9593.html

PHY Math GameTheory

shared by Beniamino Abis on 15 Jul 13 - No Cached
  • Beniamino Abis on 15 Jul 13
     
    Players with access to quantum resources can outperform classical ones. This will lead to novel joint strategies, impossible to achieve classically. Moreover, some of these strategies represent equilibrium points, leading to the notion of quantum/no-signalling Nash equilibrium.
Tom Gheysens

Revolutionizing solar energy: Quantum waves found at the heart of organic solar cells - 1 views

www.sciencedaily.com/...131212142059.htm

quantum energy organic cells BIO

shared by Tom Gheysens on 13 Dec 13 - No Cached
LeopoldS liked it
  • Tom Gheysens on 13 Dec 13
     
    pretty interesting! I am still convinced we can do something in this :)
  • Thijs Versloot on 18 Dec 13
     
    There surely must be possibilities indeed, maybe we should expand it to an RF? By coincidence, I bumped into a quantum optics PhD looking for a post-doc, who would love to give a talk in the team on his research (although very different topic) and I invited him for early January.
Thijs Versloot

Active Metasurfaces for Advanced Wavefront Engineering #Harvard - 4 views

phys.org/...ces-grant-merge-classical.html

technology optics quantum metamaterials

shared by Thijs Versloot on 02 May 14 - No Cached
  • Thijs Versloot on 02 May 14
     
    Metasurfaces have been made, but the problem is that they usually are static and for quantum optic applications the question is how to make a rapidly configurable metasurface. for this Harvard has initiated a multidisciplinary team that involves theoretical physics, metamaterials, nanophotonic circuitry, quantum devices, plasmonics, nanofabrication, and computational modeling
  • Athanasia Nikolaou on 02 May 14
     
    Reading "wavefront engineering" in the title I thought it had to do with wave manipulation in the sea. Nothing to do though. As I read further in this article, Harvard thrives in forming multidisciplinarity groups. Their practice is to call the best team in each expertise they need to merge. Not one researcher from each discipline, but teams of experienced professors and a series of graduate students. Maybe we could discuss it in the retreat!
H H

Heisenbergs Dog, the foundation of quantum computing - 1 views

photonics.anu.edu.au/...HeisenbergDog.pdf

PHY FUN

shared by H H on 07 Oct 14 - No Cached
  • H H on 07 Oct 14
     
    A Heisenberg's dog is the central unit in a quantum computer that factors prime numbers. We report the outcome of a proof-of-principle Gedankenexperiment in which the number 3 was factored and good agreement was found both with an analytical theoretical prediction and with the results of a quantum Las Vegas calculation. Other future applications of Heisenberg's dog are hinted at. The anonymous reports of the referees and our reply to them are reproduced in appendix A and appendix B respectively.
Thijs Versloot

Time 'Emerges' from #Quantum Entanglement #arXiv - 1 views

medium.com/...d5d3dc850933

science quantum relativity

shared by Thijs Versloot on 23 Oct 13 - No Cached
  • Thijs Versloot on 23 Oct 13
     
    Time is an emergent phenomenon that is a side effect of quantum entanglement, say physicists. And they have the first exprimental results to prove it
  • ...5 more comments...
  • johannessimon81 on 23 Oct 13
     
    I always feel like people make too big a deal out of entanglement. In my opinion it is just a combination of a conserved quantity and an initial lack of knowledge. Imagine that I had a machine that always creates one blue and one red ping-pong ball at the same time (|b > and |r > respectively). The machine now puts both balls into identical packages (so I cannot observe them) and one of the packages is sent to Tokio. I did not know which ball was sent to Tokio and which stayed with me - they are in a superposition (|br >+|rb >), meaning that either the blue ball is with me and the red one in Tokio or vice versa - they are entangled. So far no magic has happened. Now I call my friend in Tokio who got the ball: "What color was the ball you received in that package?" He replies: "The ball that I got was blue. Why did you send me ball in the first place?" Now, the fact that he told me makes the superpositon wavefunction collapse (yes, that is what the Copenhagen interpretation would tell us). As a result I know without opening my box that it contains a red ball. But this is really because there is an underlying conservation law and because now I know the other state. I don't see how just looking at the conserved quantity I am in a timeless state outside of the 'universe' - this is just one way of interpreting it. By the way, the wave function for my box with the undetermined ball does not collapse when the other ball is observed by my friend in Tokio. Only when he tells me does the wavefunction collapse - he did not even know that I had a complementary ball. On the other hand if he knew about the way the experiment was conducted then he would have known that I had to have a red ball - the wavefunction collapses as soon as he observed his ball. For him it is determined that my ball must be red. For me however the superposition is intact until he tells me. ;-)
  • Luzi Bergamin on 24 Oct 13
     
    Sorry, Johannes, you just develop a simple hidden-parameters theory and it's experimentally proven that these don't work. Entangeled states are neither the blue nor the red ball they are really bluered (or redblue) till the point the measurement is done.
  • Luzi Bergamin on 24 Oct 13
     
    Hm, to me this looks like a bad joke... The "emergent time" concept used is still the old proposal by Page and Whotters where time emerges from something fundamentally unobservable (the wave function of the Universe). That's as good as claiming that time emerges from God. If I understand correctly, the paper now deals with the situation where a finite system is taken as "Mini-Universe" and the experimentalist in the lab can play "God of the Mini-Universe". This works, of course, but it doesn't really tell us anything about emergent time, does it?
  • johannessimon81 on 24 Oct 13
     
    Actually, it has not been proven conclusively that hidden variable theories don' work - although this is the opinion of most physicists these days. But a non-local hidden variable would still be allowed - I don't see why that could not be equivalent to a conserved quantity within the system. As far as the two balls go it is fine to say they are undetermined instead of saying they are in bluered or redblue state - for all intents and purposes it does not affect us (because if it would the wavefunction would have collapsed) so we can't say anything about it in the first place.
  • Luzi Bergamin on 24 Oct 13
     
    Non-local hidden variables may work, but in my opinion they don't add anything to the picture. The (at least to non-physicists) contraintuitive fact that there cannot be a variable that determines ab initio the color of the ball going to Tokio will remain (in your example this may not even be true since the example is too simple...).
  • johannessimon81 on 24 Oct 13
     
    I guess I tentatively agree with you on both points. In the end there might anyway be surprisingly little overlap between the way that we describe what nature does and HOW it does it... :-D
  • Luzi Bergamin on 24 Oct 13
     
    Congratulations! 100% agree.
jcunha

Interference of thermal waves - Can heat be controlled as waves? - 1 views

phys.org/...can-heat-be-controlled-as.html

technology PHY solid state thermal management science

shared by jcunha on 26 Jun 15 - No Cached
  • jcunha on 26 Jun 15
     
    Imagine a material that only admits thermal conduction for certain temperatures. Martin Maldovan from Georgia Tech holds a tiny thermoelectric device that turns cold on one side when current is applied. Recent research has focused on the possibility of using interference effects in phonon waves to control heat transport in materials. These are exciting news (see Nature Materials paper here http://www.nature.com/nmat/journal/v14/n7/full/nmat4308.html). Heterostructure research lead to outstanding new possibilities when applied to electronic transport (e.g. in quantum well and quantum dots) and to photonics (e.g. Quantum Cascade Laser tunnable lasers). Apparently the time has come to see selective thermal control in this way! Truly exciting!!
jmlloren

Exotic matter : Insight : Nature - 5 views

www.nature.com/...index.html

nan phy

shared by jmlloren on 03 Aug 10 - Cached
LeopoldS liked it
  • jmlloren on 03 Aug 10
     
    Trends in materials and condensed matter. Check out the topological insulators. amazing field.
  • ...12 more comments...
  • Luzi Bergamin on 03 Aug 10
     
    Aparently very interesting, will it survive the short hype? Relevant work describing mirror charges of topological insulators and the classical boundary conditions were done by Ismo and Ari. But the two communities don't know each other and so they are never cited. Also a way to produce new things...
  • jmlloren on 04 Aug 10
     
    Thanks for noticing! Indeed, I had no idea that Ari (don't know Ismo) was involved in the field. Was it before Kane's proposal or more recently? What I mostly like is that semiconductors are good candidates for 3D TI, however I got lost in the quantum field jargon. Yesterday, I got a headache trying to follow the Majorana fermions, the merons, skyrnions, axions, and so on. Luzi, are all these things familiar to you?
  • Luzi Bergamin on 04 Aug 10
     
    Ismo Lindell described in the early 90's the mirror charge of what is now called topological insulator. He says that similar results were obtained already at the beginning of the 20th century... Ismo Lindell and Ari Sihvola in the recent years discussed engineering aspects of PEMCs (perfect electro-megnetic conductors,) which are more or less classical analogues of topological insulators. Fundamental aspects of PEMCs are well knwon in high-energy physics for a long time, recent works are mainly due to Friedrich Hehl and Yuri Obukhov. All these works are purely classical, so there is no charge quantisation, no considerations of electron spin etc. About Majorana fermions: yes, I spent several years of research on that topic. Axions: a topological state, of course, trivial :-) Also merons and skyrnions are topological states, but I'm less familiar with them.
  • LeopoldS on 04 Aug 10
     
    "Non-Abelian systems1, 2 contain composite particles that are neither fermions nor bosons and have a quantum statistics that is far richer than that offered by the fermion-boson dichotomy. The presence of such quasiparticles manifests itself in two remarkable ways. First, it leads to a degeneracy of the ground state that is not based on simple symmetry considerations and is robust against perturbations and interactions with the environment. Second, an interchange of two quasiparticles does not merely multiply the wavefunction by a sign, as is the case for fermions and bosons. Rather, it takes the system from one ground state to another. If a series of interchanges is made, the final state of the system will depend on the order in which these interchanges are being carried out, in sharp contrast to what happens when similar operations are performed on identical fermions or bosons." wow, this paper by Stern reads really weired ... any of you ever looked into this?
  • jmlloren on 04 Aug 10
     
    C'mon Leopold, it's as trivial as the topological states, AKA axions! Regarding the question, not me!
  • LeopoldS on 04 Aug 10
     
    just looked up the wikipedia entry on axions .... at least they have some creativity in names giving: "In supersymmetric theories the axion has both a scalar and a fermionic superpartner. The fermionic superpartner of the axion is called the axino, the scalar superpartner is called the saxion. In some models, the saxion is the dilaton. They are all bundled up in a chiral superfield. The axino has been predicted to be the lightest supersymmetric particle in such a model.[24] In part due to this property, it is considered a candidate for the composition of dark matter.[25]"
  • jmlloren on 04 Aug 10
     
    Thank's Leopold. Sorry Luzi for being ironic concerning the triviality of the axions. Now, Leo confirmed me that indeed is a trivial matter. I have problems with models where EVERYTHING is involved.
  • Luzi Bergamin on 04 Aug 10
     
    Well, that's the theory of everything, isn't it?? Seriously: I don't think that theoretically there is a lot of new stuff here. Topological aspects of (non-Abelian) theories became extremely popular in the context of string theory. The reason is very simple: topological theories are much simpler than "normal" and since string theory anyway is far too complicated to be solved, people just consider purely topological theories, then claiming that this has something to do with the real world, which of course is plainly wrong. So what I think is new about these topological insulators are the claims that one can actually fabricate a material which more or less accurately mimics a topological theory and that these materials are of practical use. Still, they are a little bit the poor man's version of the topological theories fundamental physicists like to look at since electrdynamics is an Abelian theory.
  • jmlloren on 04 Aug 10
     
    I have the feeling, not the knowledge, that you are right. However, I think that the implications of this light quantum field effects are great. The fact of being able to sustain two currents polarized in spin is a technological breakthrough.
  • LeopoldS on 04 Aug 10
     
    not sure how much I can contribute to your apparently educated debate here but if I remember well from my work for the master, these non-Abelian theories were all but "simple" as Luzi puts it ... and from a different perspective: to me the whole thing of being able to describe such non-Abelian systems nicely indicates that they should in one way or another also have some appearance in Nature (would be very surprised if not) - though this is of course no argument that makes string theory any better or closer to what Luzi called reality ....
  • Luzi Bergamin on 04 Aug 10
     
    Well, electrodynamics remains an Abelian theory. From the theoretical point of view this is less interesting than non-Abelian ones, since in 4D the fibre bundle of a U(1) theory is trivial (great buzz words, eh!) But in topological insulators the point of view is slightly different since one always has the insulator (topological theory), its surrounding (propagating theory) and most importantly the interface between the two. This is a new situation that people from field and string theory were not really interested in.
  • Dario Izzo on 04 Aug 10
     
    guys... how would you explain this to your gran mothers?
  • jmlloren on 05 Aug 10
  • LeopoldS on 07 Aug 10
     
    *you* tried *your* best .... ??
Luzi Bergamin

Physics in a Crisis - 3 views

www.rqm.ch/physics_in_a_crisis.htm

phy LHC crackpot fun

shared by Luzi Bergamin on 30 Mar 10 - Cached
  • Luzi Bergamin on 30 Mar 10
     
    Luckily I'm far away from Geneva, but this has to be said today, when the LHC starts! No, not tiny black holes will eat us (what a nonsense!), but the supernovae energy will let LHC explode!!! Pacome, I expect you to debunk this with gratest care!
  • ...2 more comments...
  • pacome delva on 30 Mar 10
     
    wtf is this! As I read this morning in the newspaper (not even a scientific one), 1 TeV is the kinetic energy of a flying mosquito... so be careful ! It seems they already sloved every thing on this website: "At the Institute for Space Quantum Physics ISQP, it was already proved in 1991-1992 that dark matter is in magnetic fields as magnetic space quantum flux." This website is the biggest source of crackpots i have seen in a long time...! (http://www.supernovae-energy.com/)
  • Ma Ru on 30 Mar 10
     
    Come on guys, this website is hilarious! "The HAITI EARTHQUAKE (...) were impossible for the Institute for Space Quantum Physics (ISQP) to compute because on one single planet was on a common line or axis with the Sun: Venus."
  • Luzi Bergamin on 30 Mar 10
     
    Unfortunately, most information I have about the guy (Hans Lehner, a Swiss) is in German, his official homepage is http://www.rqm.ch/ According to EsoWatch he is the Swiss analogue to Dr. Mills and his Blacklight power. Lehner apparently founded a company, which should have produced a "Raum-Quanten-Motor" that -- of course -- produces energy out of nothing. The theory is based on spookey forces mediated by Lehneronen. 11 Million Swiss Franks (about 8 Million Euro) were lost when the company bankrupt. And the guy is selling new stocks on his homepage again... Lehner calls another crackpot named Oliver Crane Zweistein (from Einstein being "Onestone") and himself "Dreistein". Now he is looking for Mister or Misses Vierstein. Perhaps you should apply, good luck!!
  • Nicholas Lan on 30 Mar 10
     
    i like the first line of their supernovae energy technology document "Dear potential investor:"...
pacome delva

Commercial quantum cryptography system hacked - 0 views

physicsworld.com/...42667

phy quantum_cryptography

shared by pacome delva on 21 May 10 - Cached
LeopoldS liked it
  • quantum cryptography, according to some engineers, is not without its faults. In a preprint submitted late last week to arXiv, Hoi-Kwong Lo and colleagues at the University of Toronto, Canada, claim to have hacked into a commercial quantum cryptography system by exploiting a certain practical “loophole”.
ESA ACT

An astronomical solution to an old quantum problem - 0 views

physics.aps.org/...19

PHY MAD NAN science

shared by ESA ACT on 24 Apr 09 - Cached
  • ESA ACT on 24 Apr 09
     
    An atomic physics experiment demonstrates a solution to an eighty-year-old quantum conundrum by mimicking in an atom the astronomical problem of a satellite moving in a sun-earth system. How to stabilize a wave packet?
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