Enhancing Associative Memory Recall and Storage Capacity Using Confocal Cavity QED
Enhancing Associative Memory Recall and Storage Capacity Using Confocal Cavity QED
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DOI：
10.1103/physrevx.11.021048
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发表时间：
2020-09
期刊：
影响因子：
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通讯作者：
Brendan P. Marsh;Yudan Guo;Ronen M. Kroeze;S. Gopalakrishnan;S. Ganguli;Jonathan Keeling;B. Lev
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文献类型：
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作者：
Brendan P. Marsh;Yudan Guo;Ronen M. Kroeze;S. Gopalakrishnan;S. Ganguli;Jonathan Keeling;B. Lev
我们引入了一个用于实现联想记忆的近期实验平台。它可以通过利用与简并多模光学腔耦合的有自旋的玻色子同时存储许多记忆。联想记忆是由一个共焦腔量子电动力学神经网络实现的，腔模作为突触，连接作为神经元的超辐射原子自旋系综网络。记忆被编码在自旋之间的连接矩阵中，并且可以通过光模式的输入和输出进行访问。该方案的各个方面都基于最近使用共焦腔和玻色凝聚原子所展示的技术。我们的方案有两个概念上新颖的要素。首先，它引入了一种新形式的随机自旋系统，当一个物理参数（腔内系综的位置）被调节时，该系统在铁磁态和自旋玻璃态之间插值。其次，也是更重要的，自旋通过确定性的最速下降动力学而不是格拉贝动力学弛豫。我们表明，这种非平衡量子光学方案对于联想记忆相比格拉贝动力学具有显著优势：这些动力学可以增强网络存储和回忆记忆的能力，超出标准的霍普菲尔德模型。令人惊讶的是，即使系统处于自旋玻璃相，腔量子电动力学动力学也能检索记忆。因此，该实验平台为联想记忆和自旋玻璃提供了一种新颖的物理实例，并且提供了一种不寻常的弛豫动力学形式，即使在被认为不可能的情况下也有利于记忆回忆。
We introduce a near-term experimental platform for realizing an associative memory. It can simultaneously store many memories by using spinful bosons coupled to a degenerate multimode optical cavity. The associative memory is realized by a confocal cavity QED neural network, with the cavity modes serving as the synapses, connecting a network of superradiant atomic spin ensembles, which serve as the neurons. Memories are encoded in the connectivity matrix between the spins, and can be accessed through the input and output of patterns of light. Each aspect of the scheme is based on recently demonstrated technology using a confocal cavity and Bose-condensed atoms. Our scheme has two conceptually novel elements. First, it introduces a new form of random spin system that interpolates between a ferromagnetic and a spin-glass regime as a physical parameter is tuned---the positions of ensembles within the cavity. Second, and more importantly, the spins relax via deterministic steepest-descent dynamics, rather than Glauber dynamics. We show that this nonequilibrium quantum-optical scheme has significant advantages for associative memory over Glauber dynamics: These dynamics can enhance the network's ability to store and recall memories beyond that of the standard Hopfield model. Surprisingly, the cavity QED dynamics can retrieve memories even when the system is in the spin glass phase. Thus, the experimental platform provides a novel physical instantiation of associative memories and spin glasses as well as provides an unusual form of relaxational dynamics that is conducive to memory recall even in regimes where it was thought to be impossible.