quantum mechanics tagged posts

Just as the hypothetical Schroedinger’s Cat is alive and dead at the same time, molecules hit with a burst of laser light exist in two states at once – excited (top) and unexcited. This weird quantum property allowed scientists at SLAC to make a molecular movie of excited iodine atoms in unprecedented detail. Credit: SLAC National Accelerator Laboratory

Scientists have known for a long time that an atom or molecule can also be in2 different states at once. Now researchers at the Stanford PULSE Institute and the Department of Energy’s SLAC National Accelerator Laboratory have exploited this Schroedinger’s Cat behavior to create Xray movies of atomic motion with much more detail than ever before...

Two become one: various diffraction patterns showing Rayleigh’s criterion

A team of researchers with the National University of Singapore has found a way to get around what they describe as ‘Rayleigh’s curse’—a phenomenon that happens when 2 light sources appear to coalesce as they grow closer together, limiting ability to measure the distance between them.

For many years, scientists working in a variety of fields studying the stars through a telescope or objects through a microscope have been limited by the same problem—diffraction interfering with light sources that are very close together—the wave-like nature of light causes spreading, which in turn can cause an overlap of photons striking a surface meant to be used to measure the difference between two sources.

Back in the late 1...

Hologram of a single photon: reconstructed from raw measurements (left) and theoretically predicted (right). Credit: Source: FUW

Until quite recently, creating a hologram of a single photon was believed to be impossible due to fundamental laws of physics. However, scientists at the Faculty of Physics, University of Warsaw, have successfully applied concepts of classical holography to the world of quantum phenomena. A new measurement technique has enabled them to register the first ever hologram of a single light particle, thereby shedding new light on the foundations of quantum mechanics. “We performed a relatively simple experiment to measure and view something incredibly difficult to observe: the shape of wavefronts of a single photon,” says Dr. Chrapkiewicz.

In standard photography, ind...

The NIST-4 watt balance has measured Planck’s constant to within 34 parts per billion, demonstrating that the high-tech scale is accurate enough to assist with 2018’s planned redefinition of the kilogram. Credit: J. L. Lee/NIST

A high-tech version of an old-fashioned balance scale at the National Institute of Standards and Technology (NIST) has just brought scientists a critical step closer toward a new and improved definition of the kg. The scale, NIST-4 watt balance, has conducted its first measurement of the Planck’s constant to within 34 parts per billion – demonstrating the scale is accurate enough to assist the international community with the redefinition of the kilogram, an event slated for 2018.

The redefinition-which is not intended to alter the value of the kilogram’s mass, but ...