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arXiv 0911.3579quant-ph
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在非线性自旋阵列中寻找陷阱

Finding Traps in Non-linear Spin Arrays

Marcin Wiesniak, Marcin Markiewicz

摘要:

精确地了解系统的哈密顿量是其许多应用的关键。像状态转移或量子计算这样的任务已经用线性链进行了很好的研究,但对于不具有线性结构的系统几乎没有研究。虽然这种差异不会干扰单个激励的端到端动态,但在其他子空间中,演化会发生显着变化。在这里,我们量化了线性链和伪链之间的差异,伪链在某些位置(块)有不止一个自旋。我们展示了如何估计系统中所有自旋的数量和块内耦合常数。我们还建议如何有可能消除被困在这样的块,这可能会扰乱状态转移的激发。重要的是,我们只使用端部数据,并且需要能够将系统置于最大磁化状态或最大混合状态。这可以通过控制诸如温度的全局退相干参数来获得。

英文摘要:

Precise knowledge of the Hamiltonian of a system is a key to many of its applications. Tasks such state transfer or quantum computation have been well studied with a linear chain, but hardly with systems, which do not possess a linear structure. While this difference does not disturb the end-to-end dynamics of a single excitation, the evolution is significantly changed in other subspaces. Here we quantify the difference between a linear chain and a pseudo-chain, which have more than one spin at some site (block). We show how to estimate a number of all spins in the system and the intra-block coupling constants. We also suggest how it is possible to eliminate excitations trapped in such blocks, which may disturb the state transfer. Importantly, one uses only at-ends data and needs to be able to put the system to either the maximally magnetized or the maximally mixed state. This can obtained by controlling a global decoherence parameter, such as temperature.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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