quantum physics tagged posts

This is a gold microchip. Credit: Lancaster University

1st demo of patented technology smartphone app aims to eliminate counterfeiting. Counterfeit products are a huge problem – from medicines to car parts, fake technology costs lives. Every year, imports of counterfeited and pirated goods around the world cost nearly US $0.5 trillion in lost revenue. Counterfeit medicines alone cost the industry over US $200 billion every year. They are also dangerous to our health – around a third contain no active ingredients, resulting in a million deaths a year. As the Internet of Things expands, there is the need to trust the identity of smart systems, such as the brake system components within connected and driverless cars.

But researchers exhibiting at the Royal Society Summer Science Exhibition be...

A half-quantum vortex combines circular spin flow and circular mass flow, leading to the formation of vortex pairs that can be observed experimentally. Image: Ella Maru Studio.

Gained understanding in quantum physics may be a step towards quantum computers. Researchers in Aalto University, Finland, and P.L. Kapitza Institute in Moscow have discovered half-quantum vortices in superfluid helium. This vortex is a topological defect, exhibited in superfluids and superconductors, which carries a fixed amount of circulating current. ‘This discovery of half-quantum vortices culminates a long search for these objects originally predicted to exist in superfluid helium in 1976,’ says Samuli Autti, Doctoral Candidate at Aalto University in Finland.

‘In the future, our discovery will provide access to...

A short laser pulse can ionize a helium atom and change the quantum state of the remaining electron.

When a quantum system changes its state, this is called a quantum jump. Usually, these quantum jumps are considered to be instantaneous. Now, new methods for high-precision measurements allow us to study the time evolution of these quantum jumps. On a time scale of attoseconds, there time structure becomes visible. It is he most accurate time measurement of quantum jumps to date. Quantum particles can change their state very quickly, ie “quantum jump”. An atom, for example, can absorb a photon, thereby changing into a state of higher energy. With new methods, developed at TU Wien (Vienna), it is now possible to study the time structure of such extremely fast state changes...

Vacuum fluctuations may be thought of as a flickering of the quantum light field even in total darkness. The positive (red) and negative (blue) regions are randomly distributed in space and they change constantly at high speed — similar to black-and-white noise on a TV screen with no signal input. Credit: Image courtesy of University of Konstanz

What are the properties of the vacuum, the absolute nothingness? So far, physicists have assumed that it is impossible to directly access the characteristics of the ground state of empty space. Now, a team of physicists has succeeded in doing just that. They demonstrated a first direct observation of the so-called vacuum fluctuations by using short light pulses while employing highly precise optical measurement techniques.

The duration of their lig...