This review addresses experiments on elasticity, plasticity, and flow of solid He 4 and He 3,
focusing on dislocations and other defects that are responsible for the unusual mechanical …

Our experiments show that in 4 He crystals, the binding of 3 He impurities to dislocations
does not necessarily imply their pinning. Indeed, in these crystals, there are two different …

In 2004, Kim and Chan (KC) reported a decrease in the period of torsional oscillators (TO)
containing samples of solid 4He, as the temperature was lowered below 0.2 K [Kim E, Chan …

We report on the measurements of 9.6 MHz ultrasound propagation down to 15 mK in
polycrystalline quantum solid He 4 containing 0.3 and 20 ppm He 3 impurities. The …

Quantum behavior at mesoscopic length scales is of significant interest, both from a
fundamental-physics standpoint, as well as in the context of technological advances. In this …

We developed a detailed microscopic method that describes the shear modulus anomaly of
solid helium at low temperature. The shear modulus was calculated using the pinning length …

The shear modulus of hcp^ 4 4 He decreases significantly above ∼∼ 200 mK, as^ 3 3 He
impurities unbind from dislocations, unpinning them, and softening the crystal. Here we …

The large zero-point motion and rapid atomic exchange in quantum solids like helium make
defects extremely mobile. Previous shear modulus measurements have shown that mobile …

Solid 4He shows unusual mechanical properties caused by interaction between dislocations
and 3He impurities, both of which are highly mobile due to quantum nature of helium …

Nous avons découvert que le module de cisaillement des monocristaux d'hélium-4
présentait une grande réduction dans une direction particulière quand les dislocations se …