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VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260818T053514Z
UID:https://www.mpsd.mpg.de/events/10945/17181
DTSTART:20170912T120000Z
DTEND:20170912T130000Z
CLASS:PUBLIC
CREATED:20170831T144751Z
DESCRIPTION:Ultrafast optical spectroscopy of quantum materials uncovers th
 eir intrinsic physical properties such as light-matter interactions and dy
 namics of particles and quasi-particles. In this presentation\, I will pre
 sent our ultrafast optical studies of two different electronic systems: to
 pological insulators (TIs) and two-dimensional transition metal Dichalcoge
 nides (2D TMDs). In TIs\, where Dirac-like topological surface states (TSS
 s) coexist with an underlying bulk insulator\, we have investigated ultraf
 ast dynamics of TSS Dirac fermions and plasmons\, and their interactions w
 ith phonon by using optical-pump terahertz-probe spectroscopy. We have fou
 nd that\, unlike Dirac electrons in graphene\, TSS Dirac electrons exhibit
  unique dynamic features originating from interactions with coexisting bul
 k insulator. In the studies of 2D TMDs\, we have performed ultrafast optic
 al pump-probe spectroscopy of anisotropic excitons in group-VII TMDs. We d
 iscuss coherent light-matter interactions such as excitonic optical Stark 
 effect and quantum beats\, both of which exhibit significant laser-polariz
 ation dependence\, resulting from anisotropic nature of the excitons.\nSpe
 aker: Sangwan Sim
LAST-MODIFIED:20170831T144858Z
LOCATION:CFEL (Bldg. 99)\, Room: Seminar Room IV\, O1.111
ORGANIZER;CN=Andrea Cavalleri:mailto:
SUMMARY:MPSD Seminar: Sangwan Sim - Ultrafast optical spectroscopy of topol
 ogical insulators and two-dimensional transition metal dichalcogenides
URL;VALUE=URI:https://www.mpsd.mpg.de/events/10945/17181
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