Stochastic Bose superfluid

The ideas of Mitus et al. are exploited to define the liquid state as a state of matter, in which particles perform locally ordered motion. The presence of the liquid phase is accounted for by a stochastic term in the Hamiltonian, which simulates this property of a liquid. The Bogoliubov–Lee–Huang theory of He II, recently modified by use of effective temperature scale and more stringent reduction procedure (DHSET theory) is extended, by incorporating this term into the 4 He Hamiltonian. The resulting thermodynamics accounts for effects, which are beyond the scope of other He I and He II theories, e.g., the atomic momentum distribution and excitation spectrum have the form of diffused bands, similarly as in He II; the He I, theoretical heat capacity CV(T) is a convex function, with a minimum at T min > Tλ, which qualitatively simulates experimental He I heat capacity. Other thermodynamic functions are similar to those of DHSET theory.

A Novel Microscopic Two-Stage Fermi (Precursor)-Bose (Superfluid)-Liquid Theory of High-Tc Superconductivity

We develop a novel microscopic two-stage Fermi (precursor)-Bose (superfluid)-liquid (FBL) model proposed previously beyond the conventional Fermi-liquid (i.e. BCS) and Bose–Einstein condensation (i.e. real-space pairing) theories. The electronic phase diagram of high-T c superconductors is presented. The proposed FBL theory naturally explains many key experimental findings.