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-21748
DTSTART;TZID=Europe/Berlin:20250225T110000
SEQUENCE:1740465367
TRANSP:OPAQUE
DTEND;TZID=Europe/Berlin:20250225T120000
URL:https://www.dresden-science-calendar.de/calendar/en/detail/21748
LOCATION:IFW\, Helmholtzstraße 2001069 Dresden
SUMMARY:Cerjan: An Operator-Based Approach to Topological Physics: Band Str
 uctures and Bloch Eigenstates not Required
CLASS:PUBLIC
DESCRIPTION:Speaker: Dr. Alexander Cerjan\nInstitute of Speaker: Center for
  Integrated Nanotechnologies\, Sandia National Laboratories\, Albuquerque\
 nTopics:\n\n Location:\n  Name: IFW (D2E.27\, IFW Dresden)\n  Street: Helm
 holtzstraße 20\n  City: 01069 Dresden\n  Phone: \n  Fax: \nDescription: O
 ver the past two decades\, the study of topological properties in physical
  systems has generated significant excitement\, as such systems can realiz
 e robust boundary-localized states that have a wide range of applications.
  However\, the theoretical frameworks that have been previously used to un
 derstand these phenomena are inextricably tied to band theory\, usually re
 quiring a system’s Bloch eigenstates or a projection onto the occupied su
 bspace. Thus\, the many successes of topological band theory also serve to
  highlight the current fundamental challenges facing the field\, such as t
 he difficulties in studying topology in aperiodic systems\, non-linear and
  interacting systems\, metallic systems\, and quantitatively accounting fo
 r finite size effects.  In this talk\, I will present an operator-based fr
 amework for topological physics that makes use of a system’s real-space d
 escription without the need to calculate its band structure or Bloch eigen
 states. Instead\, this framework is based on the system’s spectral locali
 zer\, and provides a set of local markers\, protected by local gaps\, for 
 every symmetry class in every physical dimension. I will discuss how this 
 operator-based framework can be used to identify topology in non-interacti
 ng metals and gapless heterostructures\, as well as photonic systems with 
 radiative environments\, and show experimental observations of a topologic
 al acoustic metal metamaterial. Moreover\, I will discuss how this framewo
 rk can be directly applied to nonlinear systems and realistic photonic sys
 tems (i.e.\, Maxwell’s equations). Finally\, I will demonstrate that the 
 spectral localizer framework can be applied to 2D electron gasses\, predic
 ting quantized Hall conductance and demonstrating how Hofstadter’s butter
 fly emerges from a uniform system as a periodic potential is turned on.  T
 his work is part-funded by Sandia National Laboratories (SNL). SNL is mana
 ged and operated by NTESS under DOE NNSA contract DE-NA0003525. .
DTSTAMP:20260315T162736Z
CREATED:20250218T063617Z
LAST-MODIFIED:20250225T063607Z
END:VEVENT
END:VCALENDAR