1. Scaling and diabatic effects in quantum annealing with a D-Wave device
- Author
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Weinberg, Phillip, Tylutki, Marek, Rönkkö, Jami M., Westerholm, Jan, Åström, Jan A., Manninen, Pekka, Törmä, Päivi, and Sandvik, Anders W.
- Subjects
Quantum Physics - Abstract
We discuss quantum annealing of the two-dimensional transverse-field Ising model on a D-Wave device, encoded on $L \times L$ lattices with $L \le 32$. Analyzing the residual energy and deviation from maximal magnetization in the final classical state, we find an optimal $L$ dependent annealing rate $v$ for which the two quantities are minimized. The results are well described by a phenomenological model with two powers of $v$ and $L$-dependent prefactors to describe the competing effects of reduced quantum fluctuations (for which we see evidence of the Kibble-Zurek mechanism) and increasing noise impact when $v$ is lowered. The same scaling form also describes results of numerical solutions of a transverse-field Ising model with the spins coupled to noise sources. We explain why the optimal annealing time is much longer than the coherence time of the individual qubits., Comment: 12 pages, 9 figures
- Published
- 2019
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