Details

Autor(en) / Beteiligte

• Veyrat, Louis
• Déprez, Corentin
• Coissard, Alexis
• Li, Xiaoxi
• Gay, Frédéric
• Watanabe, Kenji
• Taniguchi, Takashi
• Han, Zheng
• Piot, Benjamin A
• Sellier, Hermann
• Sacépé, Benjamin

Titel

Helical quantum Hall phase in graphene on SrTiO 3

Ist Teil von

• Science (American Association for the Advancement of Science), 2020-02, Vol.367 (6479), p.781-786

Ort / Verlag

United States: American Association for the Advancement of Science (AAAS)

Erscheinungsjahr

2020

Quelle

American Association for the Advancement of Science

Beschreibungen/Notizen

• The ground state of charge-neutral graphene under perpendicular magnetic field was predicted to be a quantum Hall topological insulator with a ferromagnetic order and spin-filtered, helical edge channels. In most experiments, however, an insulating state is observed that is accounted for by lattice-scale interactions that promote a broken-symmetry state with gapped bulk and edge excitations. We tuned the ground state of the graphene zeroth Landau level to the topological phase through a suitable screening of the Coulomb interaction with the high dielectric constant of a strontium titanate (SrTiO ) substrate. Robust helical edge transport emerged at magnetic fields as low as 1 tesla and withstanding temperatures up to 110 kelvin over micron-long distances. This versatile graphene platform may find applications in spintronics and topological quantum computation.