Lundi 17 septembre à 16h dans la salle E424 dans le cadre des séminaires de l’équipe HELFA, mais accessible à tous :
Dislocations in solid helium (Their effects on shear modulus and torsional-oscillator period)
Izumi Iwasa, Kanagawa University
The discovery of the anomaly in the period shift of a torsional oscillator (TO) containing solid helium-4 by Kim and Chan in 2004 stimulated a lot of experimental as well as theoretical works on a possible supersolidity of this system. Although the idea of supersolidity (i. e. the superfluid transition of solid helium) may have been a mistake, the elastic and plastic properties of solid helium are still a very unique and interesting subject for research. Defects in solid helium, especially dislocations and isotopic impurities, play an important role on these properties.
I will talk about experiments related to dislocations in solid helium and their effects on the anomalous behaviors of shear modulus and TO period.