Fig. 2 | Nature Communications

Fig. 2

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

Fig. 2

Empirical success probability vs. k* for the ASC problem on the DW2X processor. k* denotes the number of single-fermion energies that fall below the thermal energy gap at the point of the minimum gap s*. The legend entries indicate the chain parameters: (W1, W2, N). The error bars everywhere indicate 95% confidence intervals calculated using a bootstrap over different gauges and embeddings. ac Contrary to closed-system theory expectations, the success probability PG is nonmonotonic in the sector size n, first decreasing and then increasing, exponentially. Inset (a): the minimum gap (in GHz) of the chains as a function of the sector size n{1,…,20}. The solid black line denotes the operating temperature energy scale of the DW2X. df For all chains we studied the ground state success probability has a minimum at the sector size n*, where the peak in the number of single-fermion states k* occurs [compare with (ac)]. The rise and fall pattern, as well as the location of n*, are in agreement with the behavior of PG within the error bars. Inset (d): the total number of energy eigenstates that fall below the thermal energy gap as a function of the sector size n. In this case the peak position does not agree with the ground state success probability minimum

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