Fig. 4 | Nature Communications

Fig. 4

From: Finite temperature quantum annealing solving exponentially small gap problem with non-monotonic success probability

Fig. 4

Master equation results for the state populations when restricting the excited states to single-fermion states. a The population in each single-fermion state at t = tf in a one-fermion simulation. The chain parameters are N = 176, W1 = 1, W2 = 0.5, tf = 5 μs, and n = 5. With the annealing schedule given in Methods, the quantum minimum gap is at s* = t*/tf ≈ 0.424. At this point we find k* = 18 single-fermion states below the thermal energy T = 12 mK (D-Wave processor operating temperature). As expected, in one-fermion simulations, most of the population is found in the first k* states. A long tail of more energetic single-particle states beyond the first k* retain some population. b Evolution of the instantaneous ground state populations for ASCs with the same parameters as in (a), but for different sector sizes n and with two-fermion states. The ground state loses the majority of its population as it approaches the minimum gap point at t/tf = s*. The largest drop is found for n = n* = 5. Inset: magnification of the region around the minimum gap. Relaxation plays essentially no role. Instead, the population freezes almost immediately

Back to article page