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BEGIN:VEVENT
DTSTAMP:20261021T134805Z
LAST-MODIFIED:20141119T173523Z
DTSTART:20141120T140000Z
DTEND:20141120T150000Z
UID:event1360@bu.edu
URL:http://physics.bu.edu/internal/events/show/1360
SUMMARY:Measuring and Translating Electron Quasiparticle-phonon Interaction
	s on the Surface of the Topological Insulator Bi2Te3
DESCRIPTION:Featuring Colin Howard\n\nPart of the Departmental Seminars.\n\
	nDissertation Committee:  Michael El-Batanouny\, Claudio Chamon\, Robert Ca
	rey\, Karl Ludwig\, William Skocpol\n\nABSTRACT: \nThe topological insulato
	rs Bi2Se3 and Bi2Te3 have been the subjects of intense research over the pa
	st five years\, even showing potential for use in emerging technologies. An
	 important requirement for topological insulators in device-oriented applic
	ations\, such as topological quantum information and low power spintronics 
	devices\, is the availability of dissipationless surface states in the topo
	logical transport regime. This requirement means an isolated Dirac cone ful
	ly separated from bulk bands\, a Fermi level located at the Dirac point\, a
	nd suppressed electron-phonon interactions. Because of the electron quasipa
	rticles’ robustness against impurity scattering\, electron-phonon scatter
	ing should be the dominant scattering mechanism for electron quasiparticles
	 on these surfaces at finite temperatures. In this talk I will present a co
	mbined experimental\, computational\, and theoretical study of the electron
	 quasiparticle-phonon interaction on the surface of Bi2Te3. I will start by
	 describing how the measurements of the surface phonon dispersion are perfo
	rmed using helium atom surface scattering spectroscopy and will present the
	 results. I will then move on to show how one can obtain the mode-specific 
	electron phonon coupling parameter using a theoretical model derived within
	 the random phase approximation. Integrating out the wavevector dependence 
	allows us to define an average electron-phonon parameter that can be compar
	ed with results from electron spectroscopies. Finally\, I will demonstrate 
	a translation process\, devised by our group and based upon a finite temper
	ature Matsubara Green function formalism\, which allows one to take informa
	tion obtained experimentally from the phonon perspective to examine the cou
	pling signatures from the electron perspective. This novel translation appr
	oach sheds light on problems associated with traditional methods of extract
	ing the coupling parameter using electron spectroscopies and sets the requi
	site energy resolution to study the electron-phonon coupling in topological
	 insulators.\n\n![Colin](/resources/event-image/1360/c05af36_small)
LOCATION:SCI 352\, 590 Commonwealth Avenue\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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