Category Archives: measurment

Canadian researchers devise method to directly measure the quantum wavefunction

From PhysOrg.com:

To get around that problem, the team, led by Jeff Lundeen, devised a method based on “weak” measurements, whereby an observation is made that only alters the particle just a little tiny bit and gives information about just one property of the particle at a time. Taking multiple such measurements of identical copies of a particle, such as a photon, gives more and more information, eventually approaching a very close approximation to the actual state of the system. In one respect this approach is similar to the way calculus is used to measure irregularly shaped objects by cutting it into a number that approaches infinity, virtual slices, then adding up the results. When combined with more certain “strong” measurement results, the procedure provides an accurate measurement of the wavefunction.

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Moving mirrors make light from nothing

From NatureNews:

A team of physicists is claiming to have coaxed sparks from the vacuum of empty space. If verified, the finding would be one of the most unusual experimental proofs of quantum mechanics in recent years and “a significant milestone”, says John Pendry, a theoretical physicist at Imperial College London who was not involved in the study.

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Physicists calculate how to make atomic clocks super-accurate

From PhysOrg.com:

Safronova, an associate professor of physics at UD, and colleagues recently reported on their research, in which they have devised a new calculation to aid ultra-precise timekeeping. Their findings could lead to the development of an atomic clock that loses only a second in about 32 billion years — more than twice the estimated age of the universe.

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Researchers develop integrated nanomechanical sensor for atomic force microscopy

From PhysOrg.com:

As reported in Nano Letters, CNST researchers have fabricated a novel integrated sensor combining a nanomechanical cantilever probe with a high sensitivity nanophotonic interferometer on a single silicon chip. Replacing the bulky laser detection system allowed them to build cantilevers orders of magnitude smaller than those used in conventional AFMs.

Because each of these smaller structures has an effective mass less than a picogram, the detection bandwidth is dramatically increased, reducing the system response time to a few hundred nanoseconds.

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Mind Reading: Technology Turns Thought Into Action

From NPR:

Doctors have been using ECoG since the 1950s to figure out which area of the brain is causing seizures in people with severe epilepsy. But in the past decade, scientists have shown that when connected to a computer running special software, ECoG also can be used to control robotic arms, study how the brain produces speech and even decode thoughts.

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Filed under brain interfacing, brain science, neuronal activity measurment

Exotic behavior when mechanical devices reach the nanoscale

From PhysOrg.com:

Most mechanical resonators damp (slow down) in a well-understood linear manner, but ground-breaking work by Prof. Adrian Bachtold and his research group at the Catalan Institute of Nanotechnology has shown that resonators formed from nanoscale graphene and carbon nanotubes exhibit nonlinear damping, opening up exciting possibilities for super-sensitive detectors of force or mass.

The finding has profound consequences. Damping is central to the physics of nanoelectromechanical resonators, lying at the core of quantum and sensing experiments. Therefore many predictions that have been made for nanoscale electro-mechanical devices now need to be revisited when considering nanotube and graphene resonators.

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New calculations on blackbody energy set the stage for clocks with unprecedented accuracy

From PhysOrg.com:

A team of physicists from the United States and Russia announced today that it has developed a means for computing, with unprecedented accuracy, a tiny, temperature-dependent source of error in atomic clocks. Although small, the correction could represent a big step towards atomic timekeepers’ longstanding goal of a clock with a precision equivalent to one second of error every 32 billion years—longer than the age of the universe.

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