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DTSTAMP:20260920T211816Z
LAST-MODIFIED:20150303T155102Z
DTSTART:20150303T180000Z
DTEND:20150303T190000Z
UID:event1416@bu.edu
URL:http://physics.bu.edu/internal/events/show/1416
SUMMARY:2D TOPOLOGICAL INSULATORS: from 2D to 1D; from 1D to 2D
DESCRIPTION:Featuring Po-Hao Huang\n\nPart of the Preliminary Oral Exam.\n\
	nExamining Committee:  Claudio Chamon\, Michael El-Batanouny\, Emanuel Katz
	\, and Anatoli Polkovnikov\n\nAbstract:\nTopological insulators are materia
	ls that have a bulk band gap like normal insulators\, but have symmetry pro
	tected gapless edge states.  A 2D topological insulator is a quantum spin H
	all insulator protected by time reversal symmetry.\nFrom the perspective of
	 field theory\, 2D topological insulators are described by double Chern-Sim
	ons theory.  The 2+1D Chern-Simons  theory actually reduces to 1+1D Wess-Zu
	mino-Witten(WZW) model on the boundary which describes the edge states.  Ho
	wever\, the symmetry protection of the edge states are unclear in this lang
	uage.  We present a bulk-edge correspondence when certain perturbations are
	 added into the Chern-Simons theory which may be generalized to address the
	 symmetry protection.\nOn the other hand\, the fact that 1D fermionic syste
	ms can be bosonized and described by WZW models urges us to construct 2D to
	pological insulators by coupling an array of 1D wires.  With designed coupl
	ing\, we can gap out the bulk of the array and leave desired robust edge st
	ates.  We reconstruct all known short-range-entangled topological states an
	d search for long-range-entangled states that have novel physics such as no
	n-Abelian statistics and fractional central charge.
LOCATION:SCI 328\, 590 Commonwealth Avenue\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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