Observation of coherent optical information storage in an atomic medium using halted light pulses
Observation of coherent optical information storage in an atomic medium using halted light pulses
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DOI：
10.1038/35054017
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发表时间：
2001-01-25
期刊：
影响因子：
64.8
通讯作者：
Hau, LV
中科院分区：
文献类型：
--
作者：
Liu, C;Dutton, Z;Hau, LV
电磁感应透明（1-3）是一种量子干涉效应，允许光通过不透明的原子介质传播;“耦合”激光器用于产生允许传输来自“探测”激光器的共振脉冲所需的干涉。这种技术已经被用于（4-6）将光脉冲减慢和空间压缩七个数量级，导致它们完全定位和包含在原子云内（4）。在这里，我们使用电磁感应透明使激光脉冲在磁捕获的冷钠原子云中完全停止。在空间局域化的脉冲区域内，原子处于由耦合场和探测场的振幅和相位决定的叠加态。当耦合激光器突然关闭时，压缩的探测脉冲被有效地停止;最初包含在激光场中的相干信息在原子介质中被“冻结”长达1 ms。稍后耦合激光器重新打开，探测脉冲被再生：存储的相干性被读出并传输回辐射场中。我们提出了一个理论模型，揭示了该系统是自我调整，以尽量减少耗散损失在“读”和“写”操作。我们期待这种现象在量子信息处理中的应用。
Electromagnetically induced transparency(1-3) is a quantum interference effect that permits the propagation of light through an otherwise opaque atomic medium; a 'coupling' laser is used to create the interference necessary to allow the transmission of resonant pulses from a 'probe' laser. This technique has been used(4-6) to slow and spatially compress light pulses by seven orders of magnitude, resulting in their complete localization and containment within an atomic cloud(4). Here we use electromagnetically induced transparency to bring laser pulses to a complete stop in a magnetically trapped, cold cloud of sodium atoms. Within the spatially localized pulse region, the atoms are in a superposition state determined by the amplitudes and phases of the coupling and probe laser fields. Upon sudden turn-off of the coupling laser, the compressed probe pulse is effectively stopped; coherent information initially contained in the laser fields is 'frozen' in the atomic medium for up to 1 ms. The coupling laser is turned back on at a later time and the probe pulse is regenerated: the stored coherence is read out and transferred back into the radiation field. We present a theoretical model that reveals that the system is self-adjusting to minimize dissipative loss during the 'read' and 'write' operations. We anticipate applications of this phenomenon for quantum information processing.