We provide numerical evidence for a temporal quantum-mechanical interference phenomenon: time molecules (TMs). A variety of such stroboscopic states are observed in the dynamics of two interacting qubits subject to a periodic sequence of π-pulses with the period T. The TMs appear periodically in time and have a large duration, δt _TM ≫ T. All TMs are characterized by almost zero value of the total polarization and a strong enhancement of the entanglement entropy S up to the maximum value of S ≃ ln 2 indicating the presence of corresponding Bell state. Moreover, the TMs demonstrate a stroboscopic switching between the two maximally entangled Bell states and a slow leakage into other eigenstates. The TMs are generated by the commensurability of the Floquet eigenvalues and the presence of maximally entangled Floquet eigenstates. The TMs remain stable with detuned system parameters and with an increased number of qubits. In particular, we observed the TMs in the dynamics of three interacting qubits, and these TMs show a stroboscopic switching between the four Greenberger–Horne–Zeilinger states. The TMs can be observed in microwave experiments with an array of superconducting qubits.

我们为时间量子力学干涉现象提供了数值证据：时间分子 (TM)。在受周期为T的π脉冲周期序列影响的两个相互作用量子位的动力学中观察到各种此类频闪状态。TM 在时间上周期性地出现并且具有很大的持续时间，δt _TM ≫ T。所有的TM的特征在于几乎为零值的总偏振和纠缠熵的强烈增强š到的最大值小号 ≃ ln 2 表示存在对应的贝尔态。此外，TM 展示了两个最大纠缠贝尔态之间的频闪切换和缓慢泄漏到其他本征态。TMs 是由 Floquet 特征值的可公度和最大纠缠 Floquet 特征值的存在产生的。TMs 在系统参数失谐和量子位数量增加的情况下保持稳定。特别是，我们在三个相互作用的量子比特的动力学中观察了 TM，这些 TM 显示了四种 Greenberger-Horne-Zeilinger 状态之间的频闪切换。可以在微波实验中使用超导量子位阵列观察到 TM。