## Measuring A Quantum System Using 'Compressive Sensing'

Leonor Sierra, University of Rochester Researchers show momentum and position of quantum system can be determined using technique from signal processing In quantum physics, momentum and position are an example of conjugate variables. This...

# Latest Uncertainty principle Stories

International Group of Scientists Provides First Rigorous Formulation Supporting Heisenberg's Famous 1927 Uncertainty Principle WASHINGTON, April 29, 2014 /PRNewswire-USNewswire/ -- Nearly 90 years after Werner Heisenberg pioneered his uncertainty principle, a group of researchers from three countries has provided substantial new insight into this fundamental tenet of quantum physics with the first rigorous formulation supporting the uncertainty principle as Heisenberg envisioned it....

Measurement technology continues to show its potential for quantum information Until recently measuring a 27-dimensional quantum state would have been a time-consuming, multistage process using a technique called quantum tomography, which is similar to creating a 3D image from many 2D ones. Researchers at the University of Rochester have been able to apply a recently developed, alternative method called direct measurement to do this in a single experiment with no post-processing. The work...

John P. Millis, PhD for redOrbit.com - Your Universe Online Students of physics are almost universally perplexed when they are first exposed to the paradoxical world of quantum mechanics. The reason the field is so difficult to wrap one’s mind around is that the behavior of quantum systems is fundamentally different from the macroscopic world in which we spend our lives. One of the guiding principles of the quantum world is a set of statements known as Heisenberg's error-disturbance...

Physicists make first direct measurements of polarization states of light Researchers at the University of Rochester and the University of Ottawa have applied a recently developed technique to directly measure for the first time the polarization states of light. Their work both overcomes some important challenges of Heisenberg's famous Uncertainty Principle and also is applicable to qubits, the building blocks of quantum information theory. They report their results in a paper published...

April Flowers for redOrbit.com — Your Universe Online Since 1927, when Werner Heisenberg formulated the uncertainty principle, it has stood as one of the cornerstones of quantum mechanics. In a simplified form, the uncertainty principle states that it is impossible to measure anything without disturbing it. For example, any attempt to measure a particle's position must randomly change its speed. For clarity's sake, one should be aware that the uncertainty principle is not the same...

Squeezing what hasn't been squeezed before Most people attempt to reduce the little uncertainties of life by carrying umbrellas on cloudy days, purchasing automobile insurance or hiring inspectors to evaluate homes they might consider purchasing. For scientists, reducing uncertainty is a no less important goal, though in the weird realm of quantum physics, the term has a more specific meaning. For scientists working in quantum physics, the Heisenberg Uncertainty Principle says that...

Measurements at the Vienna University of Technology deepen our understanding of quantum uncertainty Heisenberg's Uncertainty principle is arguably one of the most famous foundations of quantum physics. It says that not all properties of a quantum particle can be measured with unlimited accuracy. Until now, this has often been justified by the notion that every measurement necessarily has to disturb the quantum particle, which distorts the results of any further measurements. This, however,...

The quantum world allows you to answer questions correctly when you don't even have all the information you should need No-one likes a know-it-all but we expect to be able to catch them out: someone who acts like they know everything but doesn't can always be tripped up with a well-chosen question. Can't they? Not so. New research in quantum physics has shown that a quantum know-it-all could lack information about a subject as a whole, yet answer almost perfectly any question about the...

Once we learn the relationship between a cue and its consequences"”say, the sound of a bell and the appearance of the white ice cream truck bearing our favorite chocolate cone"”do we turn our attention to that bell whenever we hear it? Or do we tuck the information away and marshal our resources to learning other, novel cues"”a recorded jingle, or a blue truck? Psychologists observing "attentional allocation" now agree that the answer is both, and they have arrived at two...

- The unit of magnetic flux density in the International System of Units, equal to the magnitude of the magnetic field vector necessary to produce a force of one newton on a charge of one coulomb moving perpendicular to the direction of the magnetic field vector with a velocity of one meter per second. It is equivalent to one weber per square meter.