photons tagged posts

Yale physicists have developed an error-correcting cat – a new device that combines the Schrödinger’s cat concept of superposition (a physical system existing in two states at once) with the ability to fix some of the trickiest errors in a quantum computation.

It is Yale’s latest breakthrough in the effort to master and manipulate the physics necessary for a useful quantum computer: correcting the stream of errors that crop up among fragile bits of quantum information, qubits, while performing a task.

A new study reporting on the discovery appears in the journal Nature. The senior author is Michel Devoret, Yale’s F.W. Beinecke Professor of Applied Physics and Physics...

A team of researchers at Stanford University has developed a theoretical way to cool down heated objects. In their paper published in the journal Physical Review Letters, the group describes their study of heat radiation and how it might be boosted to cool down a desired object.

Objects in the environment both radiate heat and receive it from the environment. Prior research has shown that heat radiated from an object does so in a spectrum, and that it peaks at a certain frequency determined by the temperature of the object. And when the number of incoming photons is greater than the number of outgoing photons, the object will grow warmer...

For the first time, physicists have successfully converted electrical signals into photons and radiated them in specific directions using a low-footprint optical antenna that is only 800 nanometers in size.

Directional antennas convert electrical signals to radio waves and emit them in a particular direction, allowing increased performance and reduced interference. This principle, which is useful in radio wave technology, could also be interesting for miniaturised light sources...

Artistic depiction of the generation of three correlated photons from quantum vacuum. Credit: Antti Paraoanu

Microwaves created at near 0K provide uniquely correlated and controllable states. Researchers at Aalto University have demonstrated the suitability of microwave signals in coding of information for quantum computing. Previous development of the field has been focusing on optical systems. They used a microwave resonator based on extremely sensitive measurement devices, ie superconductive quantum interference devices (SQUIDs). The resonator was cooled down and kept near absolute zero, where thermal motion freezes. This state corresponds to perfect darkness where no photon, a particle of electromagnetic radiation eg visible light or microwaves, is present.

However, in this state (quan...