Coherent storage of microwave excitations in rare-earth nuclear spins.
Coherent storage of microwave excitations in rare-earth nuclear spins.
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DOI：
10.1103/physrevlett.114.170503
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发表时间：
2014-12
影响因子：
8.6
通讯作者：
G. Wolfowicz;H. Maier-Flaig;R. Marino;A. Ferrier;H. Vezin;J. Morton;P. Goldner
中科院分区：
文献类型：
--
作者：
G. Wolfowicz;H. Maier-Flaig;R. Marino;A. Ferrier;H. Vezin;J. Morton;P. Goldner
计算机各部件之间的接口——从存储器到处理器再到远程通信——对量子计算机和今天的经典计算机一样至关重要。顺磁性稀土掺杂晶体，如Nd(3+):Y2SiO5(YSO)，是这种量子界面的优秀候选者：已知它们具有长光学相干寿命（通过光子进行通信），具有核自旋（存储器），并且另外具有电子自旋，可以提供与超导量子比特（处理）的混合耦合。在这里，我们研究了这三个元素中的两个，证明了Nd(3+):YSO中电子和（145）Nd核自旋态之间的相干存储和检索。我们发现核自旋相干时间在~ 5 K时可以达到9 ms，比电子自旋相干时间长约2个数量级，而电子和核自旋之间存储或检索操作的量子态和过程断层扫描显示平均状态保真度为0.86。在更低的温度和更均匀的射频激励下，时间和保真度有望进一步提高。
Interfacing between various elements of a computer--from memory to processors to long range communication--will be as critical for quantum computers as it is for classical computers today. Paramagnetic rare-earth doped crystals, such as Nd(3+):Y2SiO5(YSO), are excellent candidates for such a quantum interface: they are known to exhibit long optical coherence lifetimes (for communication via optical photons), possess a nuclear spin (memory), and have in addition an electron spin that can offer hybrid coupling with superconducting qubits (processing). Here we study two of these three elements, demonstrating coherent storage and retrieval between electron and (145)Nd nuclear spin states in Nd(3+):YSO. We find nuclear spin coherence times can reach 9 ms at ∼5 K, about 2 orders of magnitude longer than the electron spin coherence, while quantum state and process tomography of the storage or retrieval operation between the electron and nuclear spin reveal an average state fidelity of 0.86. The times and fidelities are expected to further improve at lower temperatures and with more homogeneous radio-frequency excitation.