论文标题
范德华异质结构磁性约瑟夫森连接
Van der Waals Heterostructure Magnetic Josephson Junction
论文作者
论文摘要
当两个超导体在跨铁磁铁上连接时，由于磁交换相互作用，可以调节转移的库珀对的自旋构型。所得的超电流可以在约瑟夫森交界处（JJ）[1-4]上扭转其标志。在这里，我们在范德华（Van der Waals）异质结构中演示了约瑟夫森（Josephson）阶段调制，当时由超导nbse $ _2 $ tunnel通过原子薄磁绝缘子（MI）CR $ _2 $ _2 $ ge $ _2 $ _2 $ _2 $ _6 $。我们采用基于MI JJS的超导量子干扰设备，我们探测了来自磁性屏障的双重变性非平凡的JJ相（$ ϕ $）。这个$ ϕ $ - 相JJ是由在Cr $ _2 $ _2 $ ge $ _2 $ _2 $ te $ _6 $屏障的磁域中的动量保护[5]的动量形成的。 Mi JJ中的双重变性基础状态提供了两级量子系统，可以用作超导量子设备的新的无验证的无验证组件，包括相电池[6]，内存[7,8]和量子棘轮[9,10]。
When two superconductors are connected across a ferromagnet, the spin configuration of the transferred Cooper pairs can be modulated due to magnetic exchange interaction. The resulting supercurrent can reverse its sign across the Josephson junction (JJ) [1-4]. Here we demonstrate Josephson phase modulation in van der Waals heterostructures when Cooper pairs from superconducting NbSe$_2$ tunnel through atomically thin magnetic insulator (MI) Cr$_2$Ge$_2$Te$_6$. Employing a superconducting quantum interference device based on MI JJs, we probe a doubly degenerate non-trivial JJ phase ($ϕ$) originating from the magnetic barrier. This $ϕ$-phase JJ is formed by momentum conserving tunneling of Ising Cooper pairs [5] across magnetic domains in the Cr$_2$Ge$_2$Te$_6$ barrier. The doubly degenerate ground states in MI JJs provide a two-level quantum system that can be utilized as a new disipationless component for superconducting quantum devices, including phase batteries [6], memories [7,8], and quantum Ratchets [9,10].
