International team of researchers explain the difficulty of detecting quantum effects
Are there parallel universes? And how will we know? This is one of many fascinations people hold about quantum physics. Researchers from the universities of Calgary and Waterloo in Canada and the University of Geneva in Switzerland have published a paper this week in Physical Review Letters explaining why we don't usually see the physical effects of quantum mechanics.
"Quantum physics works fantastically well on small scales but when it comes to larger scales, it is nearly impossible to count photons very well. We have demonstrated that this makes it hard to see these effects in our daily life," says Dr. Christoph Simon, who teaches in the Department of Physics and Astronomy at the University of Calgary and is one of the lead authors of the paper entitled: Coarse-graining makes it hard to see micro-macro entanglement.
It's well known that quantum systems are fragile. When a photon interacts with its environment, even just a tiny bit, the superposition is destroyed. Superposition is a fundamental principle of quantum physics that says that systems can exist in all their possible states simultaneously. But when measured, only the result of one of the states is given.
This effect is known as decoherence, and it has been studied intensively over the last few decades. The idea of decoherence as a thought experiment was raised by Erwin Schrödinger, one of the founding fathers of quantum physics, in his famous cat paradox: a cat in a box can be both dead and alive at the same time.
But, according to the authors of this study, it turns out that decoherence is not the only reason why quantum effects are hard to see. Seeing quantum effects requires extremely precise measurements. Simon and his team studied a concrete example for such a "cat" by using a particular quantum state involving a large number of photons.
"We show that in order to see the quantum nature of this state, one has to be able to count the number of photons in it perfectly," says Simon. "This becomes more and more difficult as the total number of photons is increased. Distinguishing one photon from two photons is within reach of current technology, but distinguishing a million photons from a million plus one is not."
Leanne Yohemas | EurekAlert!
SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University
Molecule flash mob
19.01.2017 | Technische Universität Wien
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences