论文标题
超导体中固定通量固定通量的量子位行为
Quantum Bit Behavior of Pinned Fluxes on Volume Defects in a Superconductor
论文作者
论文摘要
我们研究了一个基于$δ$ h = $δ$Δ$ b区域的量子固定效应。当体积缺陷在超导体中足够多时，会形成M-H曲线上的$δ$ H = $δ$ b区域，这是增加应用磁场（$δ$ H）的区域与增加磁性感应（$δ$ b）相同。该区域的磁化（M）在4 $π$ m = b -H中是恒定的。在这里，我们表明$δ$ h = $δ$δ$ b区域中通量的行为可以是Qubit的候选者。通过重复从表面到超导体中心的磁通插图和拾取滴定过程，将通量固定在体积缺陷上会作为束中的捆绑移动。在此过程中，磁通量将以磁通状态为一种磁通状态，在体积缺陷处和挑选状态，其中通量在超导体中移动。 diamagnetic特性的差异发生在体积缺陷处的固定状态与体积缺陷中默认状态之间的差异。因此，超导体的磁性特性将以$δ$ h = $δ$ b区域振荡，并且在M-H曲线中会观察到这种行为。可以通过将固定状态设置为$ \ ket {1} $，将depinned状态定为$ \ ket {0} $来使用振荡。该方法可以在更高的温度下运行，而使用约瑟夫森连接。此外，预计该设备非常简单，而解型几乎可以忽略不计。
We studied a qubit based on flux-pinning effects in $Δ$H=$Δ$B region of a superconductor. When volume defects are many enough in a superconductor, $Δ$H=$Δ$B region on M-H curve is formed, which is the region that increased applied magnetic field ($Δ$H) is the same as increasing magnetic induction ($Δ$B). Magnetization (M) is constant in the region by 4$π$M = B - H. Here we show that the behavior of fluxes in $Δ$H=$Δ$B region can be a candidate of qubit. Pinned fluxes on volume defects would move as a bundle in the region by repeating flux-pinning and pick-out depinning process from the surface to the center of the superconductor. During the process, magnetic fluxes would exist as one of states that are flux-pinning state at volume defects and pick-out depinning state in which fluxes are moving in the superconductor. A difference of diamagnetic property occurs between pinning state at volume defects and depinning state from the volume defects. Thus, diamagnetic properties of the superconductor would oscillate in $Δ$H=$Δ$B region and the behavior would be observed in M-H curve. The oscillation can be used for qubit by setting the pinning state at volume defects as $\ket{1}$ and the depinned state as $\ket{0}$. This method can operate at higher temperatures than that of using Josephson Junctions. In addition, it is expected that the device is quite simple and decoherences can be almost negligible.
