Quantum dots confine electrons to discrete energy levels and are used in optoelectronics and quantum technologies, but a dot in which confinement, magnetism and ferroelectricity all intertwine has been elusive. Researchers have now engineered such a multiferroic quantum dot in an artificial van der Waals heterostructure.
Using molecular beam epitaxy, they grew ferroelectric SnTe nanoislands on the layered magnet CrBr2. Scanning tunnelling spectroscopy, ab initio calculations and tight-binding models reveal spin-polarised discrete states confined in the islands, whose response depends on the islands' ferroelectric domains. The work links two QMAT groups, Shawulienu Kezilebieke's Synthetic Quantum Materials group and Jose Lado's Correlated Quantum Materials group, with Peter Liljeroth's Atomic Scale Physics group at Aalto; Antti Karjasilta and Adolfo Fumega are the first and last authors.
The preprint has not yet been peer reviewed.
Image: QMAT