CMSP Seminar Series @ICTP Stasi Room Thursday 19 October at 11:30: Boris SVISTUNOV

[Condensed Matter Section]

ICTP Seminar Series in Condensed Matter and Statistical Physics
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Thursday 19 October at 11:30 a.m.

Luigi Stasi Seminar Room, first floor, ICTP Leonardo building
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Boris SVISTUNOV (Physics, Univ. of Massachusetts, U.S.A.)

"Trapping Centera at the Superfluid-Mott-Insulator Criticality:
Transition between Charge-quantized States"

Abstract:
Under the conditions of superfluid-Mott-insulator criticality in two 
dimensions,
the trapping centers - i.e., local potential wells and bumps - are 
generically
characterized by an integer charge corresponding to the number of trapped
particles (if positive) or holes (if negative). Varying the strength of 
the center
leads to a transition between two competing ground states with charges 
differing
by (plus or minus) one. The hallmark of the transition scenario is a 
splitting of the
number density distortion into a half-integer core and a large halo 
carrying the
complementary charge plus/minus 1/2. The sign of the halo charge changes
across the transition. The radius of the halo diverges on the approach 
to the
critical strength of the center.