论文标题
泄漏对单线旋转Q链中离散时间晶体实现的影响
Effects of leakage on the realization of a discrete time crystal in a chain of singlet-triplet qubits
论文作者
论文摘要
我们考虑泄漏对在半导体量子点线性阵列中实现离散时间晶体（DTC）的能力的影响。该系统实现了具有有效应用磁场的ISING模型，以及可能导致计算子空间泄漏的其他术语。我们证明，在没有这些泄漏项的情况下，该模型从理论上实现了六个和八个量子位的广泛参数状态上的DTC相，对于八个Qubit的情况，参数范围更大。然后，我们重新引入泄漏项，并发现如果系统仅受到均匀的磁场的约束，则DTC相完全消失在相同的参数范围内，这不会抑制泄漏。但是，我们发现，如果系统受到从量子量到量子的交替的磁场的约束，则可以恢复DTC相，从而抑制泄漏。因此，我们表明泄漏是在ST Qubit链中实现DTC阶段的一个严重问题，但绝不是无法克服的。我们的工作表明，对于当前现有的量子点旋转量值，表现出小型系统稳定DTC的实验应该是可行的。
We consider the effects of leakage on the ability to realize a discrete time crystal (DTC) in a semiconductor quantum dot linear array being operated as a chain of singlet-triplet (ST) qubits. This system realizes an Ising model with an effective applied magnetic field, plus additional terms that can cause leakage out of the computational subspace. We demonstrate that, in the absence of these leakage terms, this model theoretically realizes a DTC phase over a broad parameter regime for six and eight qubits, with a broader parameter range for the eight-qubit case. We then reintroduce the leakage terms and find that the DTC phase disappears entirely over the same parameter range if the system is only subject to a uniform magnetic field, which does not suppress leakage. However, we find that the DTC phase can be restored if the system is instead subject to a magnetic field that alternates from qubit to qubit, which suppresses leakage. We thus show that leakage is a serious problem for the realization of a DTC phase in a chain of ST qubits, but is by no means insurmountable. Our work suggests that experiments manifesting small-system stable DTC should be feasible with currently existing quantum dot spin qubits.
