WTe2 tagged posts

A research team led by a physicist at the University of California, Riverside, has demonstrated a new magnetized state in a monolayer of tungsten ditelluride, or WTe2, a new quantum material. Called a magnetized or ferromagnetic quantum spin Hall insulator, this material of one-atom thickness has an insulating interior but a conducting edge, which has important implications for controlling electron flow in nanodevices.

In a typical conductor, electrical current flows evenly everywhere. Insulators, on the other hand, do not readily conduct electricity. Ordinarily, monolayer WTe2 is a special insulator with a conducting edge; magnetizing it bestows upon it more unusual properties.

“We stacked monolayer WTe2 with an insulating ferromagnet of several atomic layer thickness—of Cr2Ge2...

When two monolayers of WTe2 are stacked into a bilayer, a spontaneous electrical polarization appears, one layer becoming positively charged and the other negatively charged. This polarization can be flipped by applying an electric field.
Credit: Joshua Kahn

Researchers report that the 2D form of tungsten ditelluride can undergo ‘ferroelectric switching.’ Materials with ferroelectric properties can have applications in memory storage, capacitors, RFID card technologies and even medical sensors – and tungsten ditelluride is the first exfoliated 2D material known to undergo ferroelectric switching.

2D materials can be prepared in crystalline sheets as thin as a single monolayer, only one or a few atoms thick...