Periodic temporal modulation of Hamiltonians can induce geometrical and topological phenomena in the dynamics of quantum states. Using the interference between two lasers, we demonstrate an off-resonant optical lattice for a polariton condensate with controllable potential depths and nearest-neighbour coupling strength. Temporal modulation is introduced via a gigahertz frequency detuning between pump lasers, creating a polariton ‘conveyor belt’. The breaking of time-reversal symmetry causes band structures to become non-reciprocal and acquire a universal tilt given by Planck’s constant and the frequency of modulation (hΔf). The non-reciprocal tilting is connected to the non-trivial topology of the Floquet–Bloch bands, which have a finite Chern number. Detailed characterization of the lattice potential depth and its dynamics highlights the role of high-energy carriers in the formation of optical potential landscapes for polaritons, demonstrating the possibility of modulation faster than the polariton lifetime and opening a pathway towards Floquet engineering in polariton condensates.

哈密​​顿量的周期性时间调制可以在量子态动力学中引发几何和拓扑现象。利用两个激光器之间的干涉，我们展示了具有可控势深度和最近邻耦合强度的偏激子凝聚体的非共振光学晶格。通过泵浦激光器之间的千兆赫频率失谐引入时间调制，从而创建极化子“传送带”。时间反演对称性的破坏导致能带结构变得不可逆，并获得由普朗克常数和调制频率 ( h Δ f ) 给出的通用倾斜度。非互易倾斜与 Floquet-Bloch 带的非平凡拓扑有关，该带具有有限的陈数。晶格势深度及其动力学的详细表征突出了高能载流子在极化子光学势景观形成中的作用，证明了调制速度比极化子寿命更快的可能性，并为极化子凝聚态中的 Floquet 工程开辟了道路。