This scanning tunneling microscopic lense image of a graphene sheet reveals that a Wigner crystal– a honeycomb plan of electrons, like an electron ice– has actually formed inside a layered structure underneath. Credit: Image by Hongyuan Li and Shaowei Li, thanks to Nature
Breakthrough demonstrates strong state of electrons anticipated more than 90 years ago.
More than 90 years earlier, physicist Eugene Wigner anticipated that at cold temperature levels and low densities, electrons that usually zip through products would freeze into place, forming an electron ice, or what has been dubbed a Wigner crystal.
While physicists have actually obtained indirect proof that Wigner crystals exist, nobody has been able to snap an image of one– up until now.
Physicists from Berkeley Lab and UC Berkeley recently released in the journal Nature a picture of electron ice sandwiched in between two semiconductor layers. The image is proof favorable that these crystals exist.
” If you say you have an electron crystal, reveal me the crystal,” senior author Feng Wang, faculty senior scientist in Berkeley Labs Materials Sciences Division and UC Berkeley teacher of physics, informed Nature.
The Berkeley Lab and UC Berkeley group, including physicists from the labs of Wang, Michael Crommie, and Alex Zettl, established a brand-new method for picturing the crystals, which tend to “melt” when probed. By placing a graphene sheet over the semiconductor sandwich, the group was able to penetrate the Wigner crystal with a scanning tunneling microscope without melting the sample and show the crystalline lattice structure, as Wigner forecasted.
According to doctoral candidate Hongyuan Li and previous postdoctoral fellow Shaowei Li, co-first authors of the paper, the research study not just lays a strong foundation for understanding electron Wigner crystals, however also provides an approach that is usually relevant for imaging correlated electron lattices in other systems.
Recommendation: “Imaging two-dimensional generalized Wigner crystals” by Hongyuan Li, Shaowei Li, Emma C. Regan, Danqing Wang, Wenyu Zhao, Salman Kahn, Kentaro Yumigeta, Mark Blei, Takashi Taniguchi, Kenji Watanabe, Sefaattin Tongay, Alex Zettl, Michael F. Crommie and Feng Wang, 29 September 2021, Nature.DOI: 10.1038/ s41586-021-03874-9.