English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Two-dimensional (2D) mobile carriers are a wellspring of quantum phenomena.Among various 2D-carrier systems, such as field effect transistors andheterostructures, polar materials hold a unique potential; the spontaneouselectric polarization in the bulk could generate positive and negative 2Dcarriers at the surface. Although several experiments have shown ambipolarcarriers at the surface of a polar semiconductor BiTeI, their origin is yet tobe specified. Here we provide compelling experimental evidences that theambipolar 2D carriers at the surface of BiTeI are induced by the spontaneouselectric polarization. By imaging electron standing waves with spectroscopicimaging scanning tunneling microscopy, we find that positive or negativecarriers with Rashba-type spin splitting emerge at the surface correspondinglyto the polar directions in the bulk. The electron densities at the surface areconstant independently of those in the bulk, corroborating that the 2D carriersare induced by the spontaneous electric polarization. We also successfullyimage that lateral $p$-$n$ junctions are formed along the boundaries ofsubmicron-scale domains with opposite polar directions. Our study presents anovel means to endow non-volatile, spin-polarized, and ambipolar 2D carriers aswell as, without elaborate fabrication, lateral $p$-$n$ junctions of thosecarriers at atomically-sharp interfaces.

Imaging ambipolar two-dimensional carriers induced by the spontaneous electric polarization of a polar semiconductor BiTeI