WQI News

Smooth sailing for electrons in graphene

two panels in heat-map style. both panels have circles in the middle. The panel on the left has more yellow and red to the left of the circle and a bright yellow ring around the circle; the right panel has a less sharp transition of colors from left to right and no bright ring around the circles.

Physicists at the University of Wisconsin–Madison directly measured, for the first time at nanometer resolution, the fluid-like flow of electrons in graphene. The results, which will appear in the journal Science on Feb. 17, have applications in developing new, low-resistance materials, where electrical transport would be more efficient.

Graphene, an atom-thick sheet of carbon arranged in a honeycomb pattern, is an especially pure electrical conductor, making it an ideal material to study electron flow with very low resistance. Here, researchers intentionally added impurities at known distances and found that electron flow changes from gas-like to fluid-like as temperatures rise.

“All conductive materials contain impurities and imperfections that block electron flow, which causes resistance. Historically, people have taken a low-resolution approach to identifying where resistance comes from,” says Zach Krebs, a physics graduate student at UW–Madison and co-lead author of the study. “In this study, we image how charge flows around an impurity and actually see how that impurity blocks current and causes resistance, which is something that hasn’t been done before to distinguish gas-like and fluid-like electron flow.”

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Announcing the Wisconsin Quantum Computing Club (WQCC)!

The Wisconsin Quantum Computing Club has just formed! Anyone interested should fill this form out.

The first meeting is on Thursday, February 9th from 7:00pm to 8:00pm, in the CS Building, Room 1221.

graphic announcing the formation of WQCC. for full details visit the link in the story.

Preston Huft wins Wiki Science Photo Contest

Preston Huft, a graduate student in Mark Saffman’s group, was notified this week that he won the SmartElectron prize in the 2021 Wiki Science Photo Contest. Congratulations Preston!

An array of colored dots is shown.
Cesium atom array by Preston Huft. Fluorescence emitted by individual cesium-133 atoms, which have been laser cooled from a vapor in a vacuum chamber and confined in a grid of 1225 optical traps formed by laser light.

Better-than-public access to the IBM Q systems for UW–Madison

As a member of CQE, WQI has now better-than-public access to the IBM Q systems (up to Guadelupe, 16 qubit system).

To find out more about how to sign up for this capability please contact Katerina Moloni.