Universal behavior of two-dimensional 3He at low temperatures

On the example of two-dimensional (2D) 3He we demonstrate that the main universal features of its experimental temperature T-density x phase diagram [see Neumann, Nyéki, and Saunders, Science 317, 1356 (2007)10.1126/science.1143607] look like those in the heavy-fermion metals. Our comprehensive theoretical analysis of the experimental situation in 2D 3He allows us to propose a simple expression for the effective mass M*(T,x), describing all the diverse experimental facts in 2D 3He in a unified manner and demonstrating that the universal behavior of M*(T,x) coincides with that observed in heavy-fermion metals.