BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Andrea Young (UCSB) DTSTART:20210203T181500Z DTEND:20210203T194500Z DTSTAMP:20260423T021407Z UID:VSFLRC/6 DESCRIPTION:Title: O rbital magnetism in graphene heterostructures\nby Andrea Young (UCSB) as part of VSF Long Range Colloquium\n\n\nAbstract\nThe earliest reports o f ferromagnetism date to Thales of Miletus who lived and wrote around 600 BC. Thales noted the ability of natural magnetite to attract iron\, and is said to have taken this as proof that matter itself was alive. Our theori es of magnetism have evolved considerably since then: we now know that fer romagnetism arises from the interplay of the Coulomb repulsion between ele ctrons and their fermionic statistics. However\, in one sense our science has advanced only little: the vast majority of magnets\, like magnetite\, consist of ordered arrangements of the electron spins stabilized by the sp in orbit interaction. In my talk\, I will describe a new class of magnets based on the spontaneous alignment of electron orbitals. Such orbital ferr omagnetism may be a generic phenomena\, but has\, to date\, found its full est expression in graphene heterostructures in which the two dimensional o rbits of electrons in distinct momentum space valleys provide the underlyi ng degree of freedom. Because orbital degrees of freedom arise directly fr om the band wavefunctions\, they are uniquely susceptible to experimental control via materials design. Orbital magnets also enable new forms of mag netic control using in situ knobs. For instance\, orbital magnets in moire superlattice systems\, where the band structure features nontrivial topol ogy\, allow for field-effect switching of magnetic moments and the resulti ng quantized anomalous Hall effects. I will conclude with an outlook for r ealizing more exotic topological phases of matter based on orbital magneti sm.\n LOCATION:https://researchseminars.org/talk/VSFLRC/6/ END:VEVENT END:VCALENDAR