Enhancement of adiabaticity via combined control in open quantum systems

High fidelity target control over quantum systems has been realized in noisy environments. However, with the development of quantum science and technology, much higher requirements have been placed on the control precision. Meanwhile, the open system dynamics can also be modulated via engineering the reservoirs. In this work, on a basis of high fidelity control over systems, we investigate the further enhancement of the fidelity via squeezing the reservoirs. Taking the adiabatic evolution of an open spin system as an example, we find that the squeezing direction determines whether the improvement of adiabatic fidelity occurs, while the squeezing strength determines how much the fidelity is improved. Therefore, a significant enhancement in fidelity can be obtained by choosing suitable squeezing parameters. In addition, squeezing is able to slow down the decline trend that the fidelity degrades with a longer evolution time, a larger system–bath interaction strength, or a more pronounced bath Markovianity. Our work shows that squeezing enables the further improvement of high fidelity and uses a combined strategy that simultaneously controls the system and its environment, which will have potential applications in various quantum information processing tasks.