BEGIN:VCALENDAR VERSION:2.0 PRODID:www.dresden-science-calendar.de METHOD:PUBLISH CALSCALE:GREGORIAN X-MICROSOFT-CALSCALE:GREGORIAN X-WR-TIMEZONE:Europe/Berlin BEGIN:VTIMEZONE TZID:Europe/Berlin X-LIC-LOCATION:Europe/Berlin BEGIN:DAYLIGHT TZNAME:CEST TZOFFSETFROM:+0100 TZOFFSETTO:+0200 DTSTART:19810329T030000 RRULE:FREQ=YEARLY;INTERVAL=1;BYMONTH=3;BYDAY=-1SU END:DAYLIGHT BEGIN:STANDARD TZNAME:CET TZOFFSETFROM:+0200 TZOFFSETTO:+0100 DTSTART:19961027T030000 RRULE:FREQ=YEARLY;INTERVAL=1;BYMONTH=10;BYDAY=-1SU END:STANDARD END:VTIMEZONE BEGIN:VEVENT UID:DSC-22429 DTSTART;TZID=Europe/Berlin:20251110T140000 SEQUENCE:1762756697 TRANSP:OPAQUE DTEND;TZID=Europe/Berlin:20251110T150000 URL:https://www.dresden-science-calendar.de/calendar/de/detail/22429 LOCATION:IFW\, Helmholtzstraße 2001069 Dresden SUMMARY:Azhar: 3D Magnetic Textures with Mixed Topology CLASS:PUBLIC DESCRIPTION:Speaker: Dr. Maria Azhar\nInstitute of Speaker: Faculty of Phys ics and CENIDE\, University of Duisburg-Essen\nTopics:\n\n Location:\n Na me: IFW (D2E.27\, IFW Dresden)\n Street: Helmholtzstraße 20\n City: 010 69 Dresden\n Phone: \n Fax: \nDescription: Magnetic materials can host c omplex spin textures stabilized by the interplay of competing interactions . When these textures are topologically protected\, they gain robustness a gainst perturbations. In this talk\, I will introduce a range of such conf igurations—including spin spirals\, vortices\, skyrmions\, hopfions\, mul ti-q states\, and recently discovered screw dislocation defects [1]—and e xplain their stability from a topological perspective. In 3-dimensional s ystems\, topology plays an even richer role\, enabling knotted and linked structures like hopfions [2] that are characterised by an integer Hopf ind ex H. However\, traditional classifications using homotopy groups fall sho rt when magnetic textures form in non-uniform backgrounds. I will present a new framework [3] based on flux tubes of emergent magnetic field\, and t heir linking numbers\, culminating in an analytical formula for the Hopf i ndex H as a flux-weighted average of these linking numbers. This approach not only enables efficient computation of H in finite systems—avoiding t he difficulties associated with numerical evaluation of the Whitehead inte gral [4]—but also reveals that non-integer or continuously varying H can emerge in &\;quot\;mixed topology&\;quot\; states. Such textures int erpolate between distinct topological sectors\, providing new insight into the topology and tunability of magnetic textures. References [1] M. Azha r et al.\, Phys. Rev. Lett.\, 2022\, 128\, 157204. [2] Faddeev\, L.\, Niem i\, Nature\, 1997\, 387\, 58–61\; P. Sutcliffe\, Phys. Rev. Lett.\, 2017\ , 118\, 247203. [3] M. Azhar et al.\, 2024\, arXiv:2411.06929. [4] R. Knap man\, M. Azhar\, et al.\, Phys. Rev. B.\, 2024\, 111\, 134408. . DTSTAMP:20260710T175012Z CREATED:20251028T063934Z LAST-MODIFIED:20251110T063817Z END:VEVENT END:VCALENDAR