Movement of dislocations dressed with He-3 impurities in He-4 crystals

作者：Souris Fabien^*; Fefferman Andrew D; Maris Humphrey J; Dauvois Vincent; Jean Baptiste Philippe; Beamish John R; Balibar Sebastien

来源：Physical Review B, 2014, 90(18): 180103.

DOI：10.1103/PhysRevB.90.180103

Solid He-4 is a unique example of crystal where dislocations may move at macroscopic speeds with impurities attached to them. In He-4 crystals, the only impurities are He-3 atoms, whose concentration can be reduced to zero and measured down to the ppt (10(-12)) level. We present measurements of the mobility of dislocations dressed with He-3 impurities as a function of the crystal purity. They show that the damping of dislocation motion is proportional to the concentration of He-3 bound to these dislocations. It has allowed us to measure the He-3 binding energy E-B to dislocations without any ambiguity. Our results solve the controversy concerning E-B : We confirm our previously measured value 0.7 +/- 0.1 K, and we demonstrate that it cannot be 0.2 or 0.4 K as estimated by other authors. Finally, we present a simple model for the damping magnitude, where dissipation is due to the emission by moving He-3 impurities of transverse waves along the dislocation lines.

• 出版日期2014-11-14
• 单位中国地震局