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Abstract Exploring optimized processes of thermodynamics at microscale is vital to exploitation of quantum advantages relevant to microscopic machines and quantum information processing. Here, we experimentally execute a reinforcement learning strategy, using a single trapped 40Ca+ ion, for engineering quantum state evolution out of thermal equilibrium. We consider a qubit system coupled to classical and quantum baths, respectively, the former of which is achieved by switching on the spontaneous emission relevant to the qubit and the latter of which is made based on a Jaynes-Cummings model involving the qubit and the vibrational degree of freedom of the ion. Our optimized operations make use of the external control on the qubit, designed by the reinforcement learning approach. In comparison to the conventional situation of free evolution subject to the same Hamiltonian of interest, our experimental implementation presents the evolution of the states with higher fidelity while with less consumption of entropy production and work, highlighting the potential of reinforcement learning in accomplishment of optimized nonequilibrium thermodynamic processes at atomic level.

Taking a running tunnel of Shanghai Railway Airport connecting line as a demonstration application project, the synchronous technology combining shield tunneling with segment assembling is proposed based on the active control on the oil pressure of the shield thrust system, which can solve the problem of the long construction period produced by a single shield machine employed in a long-distance shield tunnel project. The principle is to make full use of the extra stroke of propulsion cylinders generated by the axial insertion of the key block to assemble segments, and the theoretical operation time of a single ring can be reduced by 31.6%. Then, a large model test platform for this synchronization technology is established to verify its feasibility and reliability, and the redistribution method of the missing thrust force is introduced during the synchronous process, which is verified by the model test. The test results show that the actuators of the shield machine respond quickly, and the errors of the cylinder pressures and total thrust force of the propulsion system are controlled within ±2%. The attitude deviation of the shield machine is controlled within ±6 mm, and the error range of the driving speed is -2 to 4 mm/min. The segments are safe with the designed overburden thickness of 33 m, and the compressive safety coefficient reaches 1.68.