15 January 2009

Quantum effects in biosystems Discover Magazine In Discover (February 2009), Mark Anderson reviews contemporary experiments in biophysics that explore the influence of quantum effects in living systems: "Could quantum mechanisms be driving some of the most elegant and inexplicable processes of life? For years experts doubted it: Quantum phenomena typically reveal themselves only in lab settings, in vacuum chambers chilled to near absolute zero. Biological systems are warm and wet. Most researchers thought the thermal noise of life would drown out any quantum weirdness that might rear its head. Yet new experiments keep finding quan­­tum processes at play in biological systems, says Christopher Altman, alumni researcher from European futurist think tank Starlab. With the advent of powerful new tools like femtosecond (10-15 second) lasers and nanoscale-precision positioning, life’s quantum dance is finally coming into view."

The Unmanned Air Force USAF In Network World and concurrent Slashdot updates, Lt. Gen. Seip discusses the future of unmanned combat aerial vehicles. "How important have unmanned aircraft become to the US military? Well, how's this: the Air Force says next year it will acquire more unmanned aircraft than manned aircraft. Air Force Lt. Gen. Norman Seip this week said the service is "all in" when it comes to developing unmanned systems and aircraft.' Next year, the Air Force will procure more unmanned aircraft than manned aircraft,' the general said. 'I think that makes a very pointed statement about our commitment to the future of unmanned aircraft, and what it brings to the fight in meeting the requirements of combatant commanders.'"

15 November 2008

Convergence08  Mountain View  " From 15-16 November 2008 – the world's most dangerous ideas will collide in Mountain View, California. Convergence08 examines the world-changing possibilities of nanotechnology and the life-changing promises of biotechnology. It is the premier forum for debate and exploration of cognitive technology ethics – and ground zero of the past and future information technology revolution. Convergence08 is an innovative, lively 'unconference– the first and only unclassified forum dedicated solely to the convergence of NBIC – nano-, bio-, information and cognitive – technology developments.

As my own UNISCA First Committee chair report to the General Assembly – "Converging Technologies: The Future of the Global Information Society" – focused specifically upon these long-term technological and cultural challenges, which we will have to confront both as a society and as a species – I have high hopes that this meeting will provide a stimulating, and unparalleled, open venue for exploration of novel ideas, discussion of alternative paradigms, and fertile grounds for brainstorming original, innovative solutions. My congratulations to the initiative of the conference organizers. I look forward to reporting back upon conclusion of the conference, as there has been an open conference wiki set up at the conference website to contribute novel ideas to the discussion.

02 October 2008

Time in Quantum Mechanics Perimeter Institute The Clock and the Quantum focuses on conceptual and technical issues concerning the role of time in quantum theory – including quantum correlations in time, histories approaches, pre- and post-selected ensembles, time and quantum measurement, and causality under the framework of quantum theory. 

Lee Smolin discusses cosmological inflation, the problem of initial conditions, and the interpretation of the "wavefunction of the universe." Lev Vaidman provides a review of the two state vector formalism, which considers backwards-evolving quantum states. Noriyuki Hatakenaka presents a new scheme for testing macrorealism without statistical treatments by combining Leggett-Garg and Greenberger-Horne-Zeilinger (GHZ) inequalities, i.e. a temporal GHZ test using quantum correlations in time. Lucian Ionescu outlines an "upgrade" of the Feynman path integral formalism – where qubits, instead of complex amplitudes – are associated within elementary transitions of a causal network structure.

The conference is first in a series of foundations conferences organized under joint collaboration between the Perimeter Institute and three Australian national universities.

09 September 2008



From Qubits to Black Holes Technion | Macquarie University "Asher Peres (1934-2005), was an Israeli scientist who is widely considered to be one of the pioneering founders of quantum information science. A student of Nathan Rosen, (the “R” of EPR), Asher codiscovered quantum teleportation, a time-reversal test for quantum entanglement, and published numerous works on the foundations of quantum science. His research legacy continues through his many research collaborators, students, textbooks and research papers."

The Technion (Israel), and Macquarie University (Australia), will host the inaugural Asher Peres International Physics School 2008, for senior undergraduates and junior postgraduates in a series of lectures ranging from quantum mechanics, theory and experiments, through to quantum gravity. Held over five days, from November 17-22 (2008), in the historic environs at Chowder Bay on Sydney Harbor, the School will feature lectures from leading scientists from around the world, including Sir Peter Knight, Artur Ekert, Christian Kurtsiefer, Chris Fuchs, Bei Lok Hu, Jason Twamley, Daniel Terno, Gavin Brennen, Alexei Gilchrist, James Rabeau, and James Cresser.

17 August 2008

Progress in Quantum Computing IQSA | LT25 | Lorentz Center – I've recently returned from a series of international conferences and workshops on superconductivity, quantum computation, entanglement and quantum coherence. In Sopot, Poland at the International Conference on Quantum Structures, much of the week was spent in long walks on the shores of the Baltic Sea, holding intense discussions on quantum information theory with Lev Levitin, who will be hosting the IQSA meeting at MIT in two years. We also continued ongoing research with Roman Zapatrin (Starlab) to advance the development of adaptive quantum networks for applications in fault-tolerant quantum computation, associative processing and pattern recognition.

Following IQSA, I moved on to the 25th triennial International Conference on Low-temperature Condensed Matter Physics, where I met with Keith Schwab following presentation of his group's recent experiments with nanomechanical resonators to probe the boundaries of quantum and classical regimes, as well as discussing present and upcoming experiments in superconducting flux qubit systems with Yasu Nakamura, John Clarke, Robert Schoelkopf, and John Martinis.

Upon conclusion of LT25, a satellite conference on Quantum Decoherence in Quantum Information Systems was held at the Lorentz Center, where I met with Vlatko Vedral to discuss long-term research initiatives in multipartite and macroscopic entanglement in condensed matter systems. Jasper van Wezel presented a review of the limits to quantum behavior related to spontaneous symmetry breaking – summarizing recent results on the quantum to classical transition, and future experiments which may elucidate the process of wavefunction collapse. Dirk Bouwmeester was generous enough to offer a tour of the experimental laboratory setup for the MiniGRAIL gravitational wave detector, which has just undergone several modifications, including improvements to the antenna, cryogenic cool-down systems, improved shielding, redesign of the capacitive transducer and fabrication of a new two-stage SQUID module for more stable operation at low temperatures.

19 June 2008

Space QUEST: Experiments with quantum entanglement in space Vienna | ESA | ISS In a recent submission to the arXiv,  Zeilinger's group at University of Vienna, Austria has proposed an experiment—Space-QUEST, Quantum Entanglement Science and Technology—for space-to-ground, entangled-photon Bell Inequality violation measurements to verify quantum nonlocality at distances over thousands of kilometers, in a joint operation between the International Space Station and a ground observatory in the European Union.

Entanglement and nonlocality have been pivotal controversies since the birth of quantum mechanics—Einstein's "spooky action at a distance" implies simultaneous, nonlocal correlations between separate entangled particles. J. S. Bell was the first to confirm the phenomenon experimentally in 1964.

Further refinements and increasing precision in succeeding experiments have consistently shown quantum mechanics to be an explicitly nonlocal theory—the outcome Einstein was most averse to accept. However, long-distance relativistic experiments, such as between orbiting satellites, have been technologically cost-prohibitive to date. The paper will be presented at the 2008 IAC Microgravity Sciences and Processes Symposium, under a proposed joint initiative between the European Space Agency and the International Space Station.

"Testing quantum correlations over distances achievable with systems placed in the Earth orbit, or even beyond, would allow to verify both the validity of quantum physics and the preservation of entanglement over distances impossible to achieve on the ground. Using the large relative velocity of two orbiting satellites, one can perform experiments on entanglement where – due to special relativity – both observers can claim that they have performed the measurement on their system prior to the measurement of the other observer. In such an experiment, it is not possible anymore to think of any local realistic mechanisms that potentially influence one measurement outcome according to the other one."

Zeilinger's group has previously conducted proof-of-principle experiments in the Canary Islands with a 144 km free-space link, using an ESA receiver telescope to receive single entangled photons, cf. Nature Physics3:481-486 (2007). A more recent experiment in Italy has demonstrated single-photon downlink communications viability from a near-earth orbit satellite, cf. New Journal of Physics10:033038 (2008).
The Reality Tests Vienna In Seed (June 2008), the Vienna experimental group discusses physical and philosophical implications of new correlations between entangled photons, which violate an inequality proposed by Leggett for nonlocal realistic theories. This new series of experiments invalidates macrorealism in quantum mechanics by more than 80 orders of magnitude. Preliminary coverage of the experimental results was first presented in Nature 446 (871) and PhysicsWorld, 20 April 2007. According to Časlav Brukner"Quantum mechanics does not always wash itself out – but to observe its effects for larger and larger objects, we would need more and more accurate measurement devices. We just do not have the sensitivity to observe the quantum effects around us. In essence, we do create the classical world we perceive. There could be other classical worlds completely different from ours."



Barcelona Photonics

Quantum networks: Entanglement of distant atoms by projective measurement University of Barcelona | ICFO | Spain Quantum cryptography is rapidly developing into a mature and robust technology for secure data transactions in financial, government and military sector applications. In arXiv 0806.1052, Zippilli et al. quantify the role of photon detector efficiency in quantum repeaters, which will be necessary to scale beyond the point-to-point networks currently employed for secure communications.

Presently, state-of-the-art systems employ atom-photon interaction to generate entanglement between distant nodes across a quantum network through projective measurement. "We assess proposals for entangling two distant atoms by measurement of emitted photons, analyzing how their performance depends on the photon detection efficiency – we believe that these concepts are generally applicable to all systems that may be considered for the creation of distant entanglement, including atomic-ensemble, photonic, and solid state implementations."

The groups's objectives are to quantify the importance of detector efficiency as applied to generating remote entanglement across quantum networks. With minor modifications, these results can be extended to the efficiency of quantum teleportation protocols that are also based on projective quantum measurement. "In all such systems, the detection efficiency will have a similar, important role for the use of the entanglement as a resource in quantum technologies."


Space-QUEST: Experiments with quantum entanglement in space Vienna | ESA | ISS In a recent submission to the arXiv,  Zeilinger's group at University of Vienna, Austria has proposed an experiment – Space-QUEST, Quantum Entanglement Science and Technology – for space-to-ground, entangled-photon Bell Inequality violation measurements to verify quantum nonlocality at distances over thousands of kilometers, in a joint operation between the International Space Station and a ground observatory in the European Union.
 
Entanglement and nonlocality have been pivotal controversies since the birth of quantum mechanics – Einstein's "spooky action at a distance" implies simultaneous, nonlocal correlations between separate entangled particles. J. S. Bell was the first to confirm the phenomenon experimentally in 1964.

Further refinements and increasing precision in succeeding experiments have consistently shown quantum mechanics to be an explicitly nonlocal theory – the outcome Einstein was most averse to accept. However, long-distance relativistic experiments, such as between orbiting satellites, have been technologically cost-prohibitive to date. The paper will be presented at the 2008 IAC Microgravity Sciences and Processes Symposium, under a proposed joint initiative between the European Space Agency and the International Space Station. 
 
"Testing quantum correlations over distances achievable with systems placed in the Earth orbit, or even beyond, would allow to verify both the validity of quantum physics and the preservation of entanglement over distances impossible to achieve on the ground. Using the large relative velocity of two orbiting satellites, one can perform experiments on entanglement where – due to special relativity – both observers can claim that they have performed the measurement on their system prior to the measurement of the other observer. In such an experiment, it is not possible anymore to think of any local realistic mechanisms that potentially influence one measurement outcome according to the other one."

Zeilinger's group has previously conducted proof-of-principle experiments in the Canary Islands with a 144 km free-space link, using an ESA receiver telescope to receive single entangled photons [Nature Physics, 3:481-486 (2007)]. A more recent experiment in Italy has demonstrated single-photon downlink communications viability from a near-earth orbit satellite [New Journal of Physics, 10:033038 (2008)].