Masaki Nakano1,2
University of Tokyo1,RIKEN Center for Emergent Matter Science (CEMS)2
Masaki Nakano1,2
University of Tokyo1,RIKEN Center for Emergent Matter Science (CEMS)2
Emergent properties and functionalities of atomically-thin van der Waals (vdW) materials named 2D materials and their integrated superstructures are one of the hot topics in condensed-matter physics and materials science. There, most of the samples are fabricated by the top-down approaches, exfoliation, pick-up, and dry-transfer techniques. On the other hand, the bottom-up synthesis by molecular-beam epitaxy (MBE) has expanded a lineup of 2D materials even to hardly-cleavable, chemically-unstable, and/or thermally-metastable compounds, providing a promising route to further exploration of novel quantum phenomena in 2D materials research. However, those MBE-based approaches have been mostly limited to spectroscopic studies using conducting graphene substrates, whereas transport studies have been less performed so far despite its essential importance presumably due to difficulties in fabrication of high-enough quality samples on insulating substrates.<br/> <br/>We have recently established a fundamental route to layer-by-layer epitaxial growth of a variety of 2D materials on insulating sapphire substrates by MBE [1], and explored transport properties of those 2D materials with reduced thickness including hardly-cleavable, chemically-unstable, and/or thermally-metastable compounds [2, 4-6] as well as their integrated superstructures [3, 7, 8]. In this presentation, we will introduce our recent achievements on the emergent 2D ferromagnetism in V<sub>5</sub>Se<sub>8</sub> epitaxial thin films [4] as well as the unique proximity and inverse proximity effects at the magnetic vdW heterostructures based on V<sub>5</sub>Se<sub>8</sub> and atomically-thin NbSe<sub>2</sub> with Zeeman-type spin-orbit interaction [7, 8].<br/> <br/>References:<br/>[1] M. Nakano <i>et al.</i>, <i>Nano Lett.</i> <b>17</b>, 5595 (2017).<br/>[2] Y. Wang <i>et al.</i>, <i>Appl. Phys. Lett.</i> <b>113</b>, 073101 (2018).<br/>[3] Y. Kashiwabara <i>et al.</i>, <i>Adv. Funct. Mater.</i> <b>29</b>, 1900354 (2019).<br/>[4] M. Nakano <i>et al.</i>, <i>Nano Lett.</i> <b>19</b>, 8806 (2019).<br/>[5] Y. Tanaka <i>et al.</i>, <i>Nano Lett.</i> <b>20</b>, 1725 (2020).<br/>[6] H. Matsuoka <i>et al.</i>, <i>Rhys. Rev. Research</i> <b>2</b>, 012064(R) (2020).<br/>[7] H. Matsuoka <i>et al.</i>, <i>Nano Lett.</i> <b>21</b>, 1807 (2021).<br/>[8] H. Matsuoka <i>et al.</i>, <i>submitted</i>.