BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//RLASKEY//CALENDEROUS//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260828T200420Z
LAST-MODIFIED:20121116T203436Z
DTSTART:20070302T170000Z
DTEND:20070302T180000Z
UID:event88@bu.edu
URL:http://physics.bu.edu/internal/events/show/88
SUMMARY:Superfluid disorder in quantum solids
DESCRIPTION:Featuring Nikolai Prokofev\, University of Massachusetts\, Amhe
	rst\n\nPart of the Biophysics/Condensed Matter Seminar Series.\n\nI will br
	iefly review old ideas on how can superfluidity occur in a crystalline soli
	d\, briefly mention a theorem that any supersolid in continuous space must 
	be in the incommensurate state and have gapless vacancies and/or interstiti
	als. In He-4 vacanices and interstitials are gapped\, and thus ideal crysta
	ls are insulating.  I will present path-integral Monte Carlo data to prove 
	that.   To explain recent experiments on the non-classical moment of inerti
	a of He-4 solids one has to consider various types of disorder. I will show
	 examples of superfluid defects in lattice and helium systems\, and discuss
	 which of them are likely to be present in experimental samples. For one th
	ing\, grain boundaries in hcp helium are generically superfluid at low T! F
	inally\, I will discuss the "ultimate" disordered superfluid state--;a heli
	um superglass which we observed to be remarkably stable at low temperatures
	 and elevated pressures.
LOCATION:SCI 352\, 590 Commonwealth Avenue\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
END:VEVENT
END:VCALENDAR