Single-layer LaBr2: Two-dimensional valleytronic semiconductor with spontaneous spin and valley polarizations

• DOI: 10.1063/1.5129311
• Publication Date: 2019-12-31T13:24:00Z
• Authors: Pei Zhao; Yandong Ma; Chengan Lei; Hao Wang; Baibiao Huang; Ying Dai
• Keywords: Valleytronics; Point reflection

The current focus of valleytronics research lies in how to produce valley polarization. Although many schemes have been broadly studied, spontaneous polarization is rarely explored. Here, we report the discovery a two-dimensional material with long-pursued spin and polarizations. Using first-principles calculations, reveal that single-layer LaBr2 dynamically thermally stable, which could be exfoliated from its bulk material. Single-layer found compelling ferromagnetic semiconductor. More interestingly, show harbors extremely rare intrinsic polarization, owing coexistence inversion symmetry time-reversal breakings. Its reaches 33 meV, sizable enough for operating room-temperature valleytronic physics. Our work thus provides promising experimental studies practical applications spintronics valleytronics.