Floquet states are a topic of intense contemporary interest, which is often induced by coherent external oscillating perturbation (e.g., laser, or microwave) which breaks the continuous time translational symmetry of the systems. Usually, electron–phonon coupling modifies the electronic structure of a crystal as a non-coherent perturbation and seems difficult to form Floquet states. Surprisingly, we found that the thermal equilibrium electron–phonon coupling in M(MoS)₃ and M(MoSe)₃ (where M is a metallic element) exhibits a coherent behavior, and the electronic structure can be described by the Floquet theorem. Such a coherent Floquet state is caused by a selective giant electron–phonon coupling, with thermodynamic phonon oscillation serving as a driving force on the electronic part of the system. The quasi-1D Dirac cone at the Fermi energy has its band gap open and close regularly. Similarly, the electric current will oscillate even under a constant voltage.

浮球状态是当代引起极大关注的话题，这通常是由相干的外部振荡扰动（例如激光或微波）引起的，这破坏了系统的连续时间平移对称性。通常，电子-声子耦合将晶体的电子结构修改为非相干扰动，似乎难以形成浮球状态。出人意料的是，我们发现M（MoS）₃和M（MoSe）₃（其中M是一种金属元素）表现出连贯的行为，电子结构可以用Floquet定理描述。这种相干的浮球状态是由选择性的巨型电子-声子耦合引起的，而热力学声子振荡则充当了系统电子部分的驱动力。费米能量处的准1D Dirac锥的带隙有规律地打开和关闭。同样，即使在恒定电压下，电流也会振荡。