Schindler Paul M, Bukov Marin
<a href="https://ror.org/01bf9rw71">Max Planck Institute for the Physics of Complex Systems</a>, Nöthnitzer Straße 38, 01187 Dresden, Germany.
Phys Rev Lett. 2024 Sep 20;133(12):123402. doi: 10.1103/PhysRevLett.133.123402.
Periodically driven systems have emerged as a useful technique to engineer the properties of quantum systems, and are in the process of being developed into a standard toolbox for quantum simulation. An outstanding challenge that leaves this toolbox incomplete is the manipulation of the states dressed by strong periodic drives. The state-of-the-art in Floquet control is the adiabatic change of parameters. Yet, this requires long protocols conflicting with the limited coherence times in experiments. To achieve fast control of nonequilibrium quantum matter, we generalize the notion of variational counterdiabatic driving away from equilibrium focusing on Floquet systems. We derive a nonperturbative variational principle to find local approximations to the adiabatic gauge potential for the effective Floquet Hamiltonian. It enables transitionless driving of Floquet eigenstates far away from the adiabatic regime. We discuss applications to two-level, Floquet band, and interacting periodically driven models. The developed technique allows us to capture nonperturbative photon resonances and obtain high-fidelity protocols that respect experimental limitations like the locality of the accessible control terms.
周期性驱动系统已成为一种用于设计量子系统特性的有用技术，并且正在发展成为量子模拟的标准工具箱。使这个工具箱尚不完整的一个突出挑战是对由强周期性驱动所修饰的状态进行操控。弗洛凯控制的当前技术水平是参数的绝热变化。然而，这需要长的协议，这与实验中有限的相干时间相冲突。为了实现对非平衡量子物质的快速控制，我们将变分反绝热驱动的概念推广到远离平衡的情况，重点关注弗洛凯系统。我们推导了一个非微扰变分原理，以找到有效弗洛凯哈密顿量的绝热规范势的局部近似。它能够在远离绝热区域的情况下对弗洛凯本征态进行无跃迁驱动。我们讨论了在二能级、弗洛凯能带和相互作用周期性驱动模型中的应用。所开发的技术使我们能够捕捉非微扰光子共振，并获得符合实验限制（如可访问控制项的局部性）的高保真协议。
