Quantum tunneling is a phenomenon in which a quantum state traverses energy barriers above the energy of the state itself [1,2]. Tunneling has been hypothesized as an advantageous physical resource for optimization [3][4][5][6][7]. Here we present the first experimental evidence of a computational role of multiqubit quantum tunneling in the evolution of a programmable quantum annealer. We develop a theoretical model based on a NIBA Quantum Master Equation to describe the multiqubit dissipative tunneling effects under the complex noise characteristics of such quantum devices. We start by considering a computational primitive, an optimization problem consisting of just one global and one false minimum. The quantum evolutions enable tunneling to the global minimum while the corresponding classical paths are trapped in a false minimum. In our study the non-convex potentials are realized by frustrated networks of qubit clusters with strong intra-cluster coupling. We show that the collective effect of the quantum environment is suppressed in the "critical" phase during the evolution where quantum tunneling "decides" the right path to solution. In a later stage dissipation facilitates the multiqubit tunneling leading to the solution state. The predictions of the model accurately describe the experimental data from the D-Wave Two quantum annealer at NASA Ames. In our computational primitive the temperature dependence of the probability of success in the quantum model is opposite to that of the classical paths with thermal hopping. Specifically, we provide an analysis of an optimization problem with sixteen qubits, demonstrating eight qubit tunneling that increases success probabilities. Furthermore, we report results for larger problems with up to 200 qubits that contain the primitive as subproblems.

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on output in the service sectors. They do not find any such effect for the manufacturing sectors. The paper shows that the differential effect on services and manufacturing arises because service sectors are more skill intensive.

JEL classification: J080 K31 L81 O53 Keywords: Labor regulations India Employment Retail Informality Amin, Mohammad-Labor regulation and employment in India's retail storesA new dataset of 1948 retail stores in India shows that 27% of the stores find labor regulations as a problem for their business. Using these data, we analyze the effect of labor regulations on employment at the store level. We find that flexible labor regulations have a strong positive effect on job creation. Our estimates show that labor reforms are likely to increase employment by 22% of the current level for an average store. We also address the issue of informality in India's retail sector. Our findings suggest that more flexible labor laws can encourage firms to operate in the more efficient formal retail sector. According to our estimates, labor reforms could reduce the level of informality by as much as 33%.