Floquet states in dissipative open quantum systems
Floquet states in dissipative open quantum systems
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DOI：
10.1088/1361-6455/abb127
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发表时间：
2020-11-28
影响因子：
1.6
通讯作者：
Rubio, A.
中科院分区：
文献类型：
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作者：
Sato, S. A.;De Giovannini, U.;Rubio, A.
我们基于麦克斯韦-布洛赫方程的完全解，从理论上研究了周期性驱动的开放量子系统非平衡稳态的基本性质。在谐振驱动条件下，我们发现横向弛豫（也称为退相干）显着破坏了 Floquet 态的形成，而纵向弛豫对其没有直接影响。此外，通过评估非平衡稳态的准能谱，我们证明只要退相干时间短至拉比周期的三分之一，就可以观察到拉比分裂。此外，我们发现，一旦驱动场强度足够强，当退相干时间远短于驱动周期时，即使在显着耗散的情况下，也可以形成Floquet态。在非共振条件下，我们证明即使在弱场状态下也可以实现 Floquet 态，因为系统没有被激发，退相干机制也没有被激活。一旦场强变得足够强，系统就可以通过多光子吸收来激发，并且退相干过程变得活跃。因此，即使在非谐振条件下，Floquet 状态也会受到环境的显着干扰。因此，我们在这里表明，抑制从光到物质的能量转移是在谐振和非谐振条件下实现 Floquet 态的关键条件，不仅因为它可以防止材料损坏，而且因为它有助于保持相干性。
We theoretically investigate basic properties of nonequilibrium steady states of periodically-driven open quantum systems based on the full solution of the Maxwell-Bloch equation. In a resonant driving condition, we find that the transverse relaxation, also known as decoherence, significantly destructs the formation of Floquet states while the longitudinal relaxation does not directly affect it. Furthermore, by evaluating the quasienergy spectrum of the nonequilibrium steady states, we demonstrate that Rabi splitting can be observed as long as the decoherence time is as short as one third of the Rabi-cycle. Moreover, we find that Floquet states can be formed even under significant dissipation when the decoherence time is substantially shorter than the cycle of driving, once the driving field strength becomes strong enough. In an off-resonant condition, we demonstrate that the Floquet states can be realized even in weak field regimes because the system is not excited and the decoherence mechanism is not activated. Once the field strength becomes strong enough, the system can be excited by multi-photon absorption and the decoherence process becomes active. As a result, the Floquet states are significantly disturbed by the environment even in the off-resonant condition. Thus, we show here that the suppression of energy transfer from light to matter is a key condition for the realization of Floquet states in both on- and off-resonant conditions not only because it prevents material damage but also because it contributes to preserving coherence.