Showing posts with label quantum mechanics. Show all posts
Showing posts with label quantum mechanics. Show all posts

Monday, May 15, 2017

Pure magic: Direct counterfactual communication via quantum Zeno effect

Not really, it's just science (or physics)...

PNAS (Proceedings of the National Academy of Sciences of the United States of America) published a manuscript titled "Direct counterfactual communication via quantum Zeno effect" by Cao et al.

The article's significance, submitted in August 2016, is given as:

"Recent theoretical studies have shown that quantum mechanics allows counterfactual communication, even without actual transmission of physical particles, which raised a heated debate on its interpretation. Although several papers have been published on the theoretical aspects of the subject, a faithful experimental demonstration is missing. Here, by using the quantum Zeno effect and a single-photon source, direct communication without carrier particle transmission is implemented successfully. We experimentally demonstrate the feasibility of direct counterfactual communication with the current technique. The results of our work can help deepen the understanding of quantum mechanics. Furthermore, our experimental scheme is applicable to other quantum technologies, such as imaging and state preparation."


(Credit: Cao et al)

How help you grok the article, here are some links:
Be warned, these will take a while to read (and believe) if you are not a physicist.



Tuesday, February 2, 2016

Physics, Math and Pi

Tamar Friedmann and Carl R. Hagen,  ar University of Rochester, recently published a manuscript titled 'looked at 'Quantum Mechanical Derivation of the Wallis Formula for π'.'

They have been looking at the variational computation of the spectrum of the hydrogen atom. They start with Schrödinger equation for the hydrogen atom, given by:

H . ψ  =  ( - h2.∇2 / 2.m  -  e2 / r) . ψ  =  E . ψ

and arrive at the famous pre-Newtonian formula for pi, derived by John Wallis in 1655.

360 years after a mathematical derivation of pi, physicists come up with a physical derivation for quantum energy levels that is identical to it. The universe never fails to amaze.

Two pages from the book "Arithmetica Infinitorum," by John Wallis. In the table on the left page, the square that appears repeatedly denotes 4/pi, or the ratio of the area of a square to the area of the circumscribed circle. Wallis used the table to obtain the inequalities shown at the top of the page on the right that led to his formula. Credit: Digitized by Google.

Here are some related links: