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BEGIN:VEVENT
DTSTAMP:20260912T123444Z
LAST-MODIFIED:20141020T160930Z
DTSTART:20141027T153000Z
DTEND:20141027T163000Z
UID:event1341@bu.edu
URL:http://physics.bu.edu/internal/events/show/1341
SUMMARY:Emergent Magnetic Monopole Charges in a Two Qubit System
DESCRIPTION:Featuring Tiago Souza\n\nPart of the Preliminary Oral Exam.\n\n
	Examining Committee:\n\nAnatoli Polkovnikov\, Claudio Chamon\, Shyam Errami
	lli and Ami Katz \n\nAbstract:\nWe introduce a simple Hamiltonian describin
	g the interaction of two coupled qubits (modeled by two spins) with externa
	l magnetic elds. Borrowing ideas from topology\, we calculate the Berry con
	nection and curvature\, as well as the Chern number\, and a natural mapping
	 shows that the latter is equivalent to the magnetic eld produced by monopo
	le charges in real space. We suggest a method for measuring the magnetic mo
	nopole\ncharge density (i. e.\, the ground state degeneracies in a coupled 
	XY quantum system) and detail its motion as external parameters are varied.
	 Using symmetry arguments\, we derive the result that the Berry connec-\nti
	on ~A is proportional to the expectation value of z tot in the ground state
	\, thereby allowing for measurements to be obtained for all the quantities 
	related to the Berry curvature\, ~F = r  ~ A\, by simply measuring hz toti.
	\n\nUsing Maxwell's equations with the addition of magnetic monopoles\, we 
	obtain the eective charge density and the current density as a function of 
	the parameters changed. We show how particular choices for param-\neters gi
	ve rise to peculiar kinds of motion of the monopole charges\, how one can g
	o from magnetic monopole charges to continuous charge distributions like ri
	ngs and surfaces by properly changing the system's symmetries through its p
	arameters\, and probe the interesting but as of yet unexplored\nconsequence
	s on r  ~F as said changes are made.\n\n![Tiago] (/resources/event-image/13
	41/c5a23f3_small)
LOCATION:SCI 328\, 590 Commonwealth Avenue\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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