Fig. 1: Phase diagram and critical scaling for the two-dimensional quantum spin glass.
From: The quantum transition of the two-dimensional Ising spin glass
a, Phase diagram for a two-dimensional Ising spin glass in terms of temperature T and transverse field Γ. For all T > 0, the system is disordered when studied at large length scales, so that it is in the paramagnetic phase (PM). At T = 0, the ground state seems disordered for Γ > Γc (from the point of view of the computational basis). For Γ < Γc, we encounter the spin-glass phase (SG), which is different for every disorder realization (equation (1)). b, Our finite-size scaling analysis (see, for example, refs. 48,60) of the critical point at T = 0 and Γ = Γc, in terms of the parameter k that represents Γ in the Trotter–Suzuki formulation (‘The Trotter–Suzuki formula’ in Methods; k grows as Γ decreases). Left, correlation length ξ(3) in units of the lattice size L versus k. The curves for the different L’s intersect at the critical point kc ≈ 0.29. Right, data in the left-hand panel of b, when represented as a function of the scaling variable L1/ν(k − kc) with 1/ν = 0.7, converge to a limiting curve as L grows. Points in b are statistical averages, and errors are one standard deviation. Our data set is fully described in Extended Data Table 1.
