Atomic arrays provide an important quantum optical platform with photon-mediated dipole–dipole interactions that can be engineered to realize key applications in quantum information processing. A major obstacle for such applications is the fast decay of the excited states. By controlling two-band Bloch oscillations of single excitation in an atomic array under an external magnetic field, here we show that exotic subradiance can be realized and maintained with orders of magnitude longer than the spontaneous decay time in atomic arrays with the finite size. The key finding is to show a way for preventing the wavepacket of excited states scattering into the dissipative zone inside the free space light cone, which therefore leads to the excitation staying at a subradiant state for an extremely long decay time. We show that such operation can be achieved by introducing a spatially linear potential from the external magnetic field in the atomic arrays and then manipulating interconnected two-band Bloch oscillations along opposite directions. Our results also point out the possibility of controllable switching between superradiant and subradiant states, which leads to potential applications in quantum storage.

中文翻译：

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原子阵列中双波段布洛赫振荡的极端单激发亚辐射

原子阵列提供了一个重要的量子光学平台，具有光子介导的偶极子-偶极子相互作用，可以通过设计来实现量子信息处理中的关键应用。此类应用的主要障碍是激发态的快速衰减。通过控制外部磁场下原子阵列中单次激发的两带布洛赫振荡，我们表明可以实现并维持比有限尺寸原子阵列中的自发衰变时间长几个数量级的奇异亚辐射。关键发现是展示一种防止激发态波包散射到自由空间光锥内的耗散区的方法，从而导致激发态在极长的衰减时间内保持在次辐射态。我们证明，这种操作可以通过在原子阵列中引入来自外部磁场的空间线性势，然后沿相反方向操纵互连的双能带布洛赫振荡来实现。我们的结果还指出了超辐射态和次辐射态之间可控切换的可能性，这导致了量子存储中的潜在应用。