quantum circuit tagged posts

Using ultracold atoms and laser light, researchers recreated the behavior of a Josephson junction—an essential component of quantum computers and voltage standards. The appearance of Shapiro steps in this atomic system reveals a deep universality in quantum physics and makes elusive microscopic effects visible for the first time.

Josephson junctions play a central role in modern physics and technology. They enable extremely precise measurements, define the international standard for electrical voltage, and serve as essential components inside many quantum computers...

Researchers at Delft University of Technology have created a quantum circuit that enables them to listen to the weakest radio signal allowed by quantum mechanics. This new quantum circuit opens the door to possible future applications in areas such as radio astronomy and medicine (MRI). It also enables researchers to do experiments that can shed light on the interplay between quantum mechanics and gravity.

We have all been annoyed by weak radio signals at some point in our lives: our favourite song in the car turning to noise, being too far away from our wifi router to check our email...

Layout of IBM’s four superconducting quantum bit device.
Credit: IBM Research

Scientists have now demonstrated for the first time developed a quantum circuit that can solve a problem that is unsolvable using any equivalent classical circuit. Conventional computers obey the laws of classical physics. They rely on the binary numbers 0 and 1. These numbers are stored and used for mathematical operations. In conventional memory units, each bit – the smallest unit of information – is represented by a microscopic dot on a microchip. Each of these dots can hold a charge that determines whether the bit is set to 1 or 0.

In a quantum computer, however, a bit can be both 0 and 1 at the same time. This is because the laws of quantum physics allow electrons to be in multiple places at one time...