标题： 快速高效的长程自旋-$\frac{1}{2}$模型中的远距离量子态传输 显示英文标题

标题： Fast and efficient long-distance quantum state transfer in long-range spin-$\frac{1}{2}$ models

摘要： 量子态传输在长自旋-$\frac{1}{2}$线性链中超越了最近邻耦合方案进行了研究。 利用次近邻哈密顿量色散关系的特性，表明通过最小工程，即在两个端点位置施加一个局域磁场，并仅对端部几个对称修改的相邻间耦合进行调整，就可以实现平均传输保真度高于$99\%$。 在主导阶次下，所需时间与链的长度成线性关系。 这种快速、高质量的量子态传输基于通过局域磁场在色散关系线性区域中心的波包的弹道传播。 同时，波包宽度由链端的相邻间耦合调制，其值通过一个精心设计的遗传算法确定，主要被限制在色散关系的线性区域内。 我们的耦合方案适用于任意的次近邻相邻间耦合值，并可直接应用于更远距离的耦合方案。 显示英文摘要

摘要： Quantum state transfer is investigated beyond the nearest-neighbour coupling scheme in long spin-$\frac{1}{2}$ linear chains. Exploiting the properties of the next-nearest neighbour Hamiltonian's dispersion relation, it is shown that with minimal engineering, i.e., an on-site magnetic field on the two end sites and only a few symmetrically-modified end inter-site couplings, an average transfer fidelity above $99\%$ can be achieved. To leading order, the required time scales linearly with the length of the chain. Such a fast, high-quality quantum state transfer is based on the ballistic propagation of the wave packet centred in the linear region of the dispersion relation by means of the on-site magnetic field. At the same time, the wave packet width, modulated by the inter-site couplings at the chain ends, whose values are found via a carefully designed genetic algorithm, is constrained mostly in the linear region of the dispersion relation. Our coupling scheme is shown to hold for arbitrary values of the next-nearest inter-site coupling and can be straightforwardly applied to longer range coupling schemes.