Giant isochoric compressibility of solidHe4: The bistability of superclimbing dislocations

Abstract

A significant accumulation of matter in solid4 He observed during the superflow events, dubbed as the giant isochoric compressibility (or the syringe effect), is discussed within the model of dislocations with superfluid core. It is shown that solid 4 He in a contact with superfluid reservoir can develop a bistability with respect to the syringe fraction, with the threshold for the bias by chemical potential determined by a typical free length of dislocations with superfluid core. The main implications of this effect are: hysteresis and strongly non-linear dynamical behavior leading to growth, proliferation and possibly exiting from a crystal of superclimbing dislocations. Three major channels for such dynamics are identified: i) injection and inflation of the prismatic loops from the boundary; ii) Bardeed-Herring generation of the loops in the bulk; iii) helical instability of the screw dislocations. It is argued that the current experiments are likely to be well in this regime. Several testable predictions for the time and the bias dependencies of the dynamics are suggested.

Emergence of Luttinger liquid behavior of a superclimbing dislocation

“…As mentioned in Ref. 21 , the current experiments 7,8 and also 9 are likely to be in the regime of large µ, that is, in the dislocation rough state induced by the bias where κ = κ 1 = κ g , Eq. (3), even at T = 0.…”

“…21 , presence of an ensemble of dislocations modifies the isochoric compressibility. The main effect comes from the overall compression of the solid as extra matter ∆N enters (exits) it.…”

2D Dilute Bose Mixture at Low Temperatures

“…in an optical lattice [24,25,26,27,28,29,30] that are characterized by nontrivial phase diagrams the equilibrium properties of the homogeneous binary 2D bosonic gases with continuous translational symmetry are less studied. Reliable results for the stability condition of the low-density mixtures were obtained in Refs.…”

Superclimbing dislocation with a Coulomb-type interaction between jogs

“…As discussed in Refs. 11,15 for G 2 = 0, the diverging κ for one dislocation means that a sample of solid 4 He permeated by a uniform network of superclimbing dislocations exhibits a linear 3D response on chemical potential which is independent of the dislocation density, with its magnitude being comparable with the 3D compressibility of a liquid. This property is the basis for the syringe effect 8,9 . At finite G 2 the 3D response becomes suppressed logarithmically with respect to a typical length L of superclimbing segments.…”

“…17 . We emphasize that the model (15,16,17) represents a dual version of the original model (4,1,2,3) -where the original continuous variables (with the phase φ being defined modulo 2π) are replaced by the discrete bond currents J x , J τ and the constraint (17).…”