Category Technology/Electronics

Electrodes stretch diamond strings to increase the frequency of atomic vibrations to which an electron is sensitive, just like tightening a guitar string increases the frequency or pitch of the string. The tension quiets a qubit’s environment and improves memory from tens to several hundred nanoseconds, enough time to do many operations on a quantum chip. (Second Bay Studios/Harvard SEAS)

A process similar to guitar tuning improves storage time of quantum memory. A quantum internet promises completely secure communication. But using quantum bits or qubits to carry information requires a radically new piece of hardware – a quantum memory. This atomic-scale device needs to store quantum information and convert it into light to transmit across the network.

A major challenge to this vision i...

These are small diameter carbon nanotubes grown on a stainless steel surface. Credit: Pint Lab/Vanderbilt Univerity

Imagine a box you plug into the wall that cleans your toxic air and pays you cash. That’s essentially what Vanderbilt University researchers produced after discovering the blueprint for turning CO2 into the most valuable material ever sold – carbon nanotubes with small diameters.

Carbon nanotubes are supermaterials that can be stronger than steel and more conductive than copper. The reason they’re not in every application from batteries to tires is that these amazing properties only show up in the tiniest nanotubes, which are extremely expensive...

Electrical control of third harmonic generation (THG) can be obtained in single-layer graphene. In THG three low-frequency photons (red) sum up to generate one high-frequency (blue) photon. For this reason, THG can be used for optical frequency converters. Credit: Giancarlo Soavi, University of Cambridge

Technology could lead to new devices for faster, more reliable ultra-broad bandwidth transfers. For the first time, researchers demonstrated how electrical fields boost the non-linear optical effects of graphene. Graphene, among other materials, can capture photons, combine them, and produce a more powerful optical beam. This is due to a physical phenomenon called the optical harmonic generation, which is characteristic of nonlinear materials...

Ion–photon entanglement scheme and quantum-state tomography.

Physicists have succeeded in entangling a single atom with a single photon in the telecom wavelength range. This constitutes a basic building block for transmission of quantum information over long distance with low loss. Communication using quantum states offers ultimate security, because eavesdropping attempts perturb the signal and would therefore not remain undetected. For the same reason, though, long-distance transmission of that information is difficult. In classical telecommunication, the increasing attenuation of the signal is counteracted by measuring, amplifying and re-sending it in so-called repeater stations, but this turns out to be as detrimental to the quantum information as an eavesdropper.

Therefore, a differe...