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BEGIN:VEVENT
DTSTAMP:20260814T121958Z
LAST-MODIFIED:20121116T203436Z
DTSTART:20101117T160000Z
DTEND:20101117T170000Z
UID:event730@bu.edu
URL:http://physics.bu.edu/internal/events/show/730
SUMMARY:Topological characterization of periodically driven systems 
DESCRIPTION:Featuring Takuya Kitagawa\, Harvard University\n\nPart of the C
	ondensed Matter Theory Seminar Series.\n\nAbstract:\nTopological properties
	 of physical systems can lead to robust\nbehaviors that are insensitive to 
	microscopic details. Such\ntopologically robust phenomena are not limited t
	o static systems\nbut can also appear in driven quantum systems. In this ta
	lk\, we show that the Floquet operators of periodically driven systems can 
	be divided into topologically distinct (homotopy) classes\, and give a simp
	le physical interpretation of this classification in terms of the spectra o
	f Floquet operators. \nSystems whose Floquet operators belong to the trivia
	l class\nsimulate the dynamics generated by time-independent Hamiltonians\,
	\nwhich can be topologically classified according to the schemes developed 
	for static systems. One set of examples of such dynamics are provided by qu
	antum walks\, which we previously showed to realize all of the topological 
	phases classified in 1 and 2 dimensions.\nWe demonstrate these principles t
	hrough an example of\na periodically driven two--;dimensional hexagonal lat
	tice model\nwhich exhibits several topological phases. Remarkably\, one of 
	these phases supports chiral edge modes even though the bulk is topological
	ly trivial.\n\nReference:\nT.Kitagawa\, E.Berg\, M.Rudner\, E.Demler\, http
	://arxiv.org/abs/1010.6126\nSee also T.Kitagawa et al\, Phys.Rev. A 82\, 03
	3429 (2010)
LOCATION:SCI 328\, 590 Commonwealth Avenue\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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