Golod Taras, Morlet-Decarnin Lise, Krasnov Vladimir M
Department of Physics, Stockholm University, AlbaNova University Center, SE-10691, Stockholm, Sweden.
Nat Commun. 2023 Aug 15;14(1):4926. doi: 10.1038/s41467-023-40654-7.
The lack of dense random access memory is one of the main bottlenecks for the creation of a digital superconducting computer. In this work we study experimentally vortex-based superconducting memory cells. Three main results are obtained. First, we test scalability and demonstrate that the cells can be straightforwardly miniaturized to submicron sizes. Second, we emphasize the importance of conscious geometrical engineering. In the studied devices we introduce an asymmetric easy track for vortex motion and show that it enables a controllable manipulation of vortex states. Finally, we perform a detailed analysis of word and bit line operation of a 1 × 1 μm cell. High-endurance, non-volatile operation at zero magnetic field is reported. Remarkably, we observe that the combined word and bit line threshold current is significantly reduced compared to the bare word-line operation. This could greatly improve the selectivity of individual cell addressing in a multi-cell RAM. The achieved one square micron area is an important milestone and a significant step forward towards creation of a dense cryogenic memory.
缺乏密集随机存取存储器是创建数字超导计算机的主要瓶颈之一。在这项工作中，我们对基于涡旋的超导存储单元进行了实验研究。获得了三个主要结果。首先，我们测试了可扩展性，并证明这些单元可以直接缩小到亚微米尺寸。其次，我们强调了有意识的几何工程的重要性。在我们研究的器件中，我们引入了一条用于涡旋运动的不对称易通道，并表明它能够对涡旋态进行可控操纵。最后，我们对一个1×1μm单元的字线和位线操作进行了详细分析。报告了在零磁场下的高耐久性、非易失性操作。值得注意的是，我们观察到与裸字线操作相比，组合字线和位线的阈值电流显著降低。这可以大大提高多单元随机存取存储器中单个单元寻址的选择性。所实现的一平方微米面积是一个重要的里程碑，也是朝着创建密集低温存储器迈出的重要一步。
