Locking of electron spin coherence above 20 ms in natural silicon carbide
Locking of electron spin coherence above 20 ms in natural silicon carbide
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DOI：
10.1103/physrevb.95.161201
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发表时间：
2016-02
影响因子：
3.7
通讯作者：
D. Simin;H. Kraus;A. Sperlich;T. Ohshima;G. Astakhov;V. Dyakonov
中科院分区：
文献类型：
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作者：
D. Simin;H. Kraus;A. Sperlich;T. Ohshima;G. Astakhov;V. Dyakonov
量子信息科学的挑战之一是在自然生长的固态系统中实现超长自旋相干。到目前为止，通常需要同位素工程来抑制与核自旋相互作用引起的主要弛豫机制。作者在这里证明，这一雄心勃勃的目标也可以在具有天然同位素丰度的二元化合物中实现。通过两种效应的结合，它们获得了自旋锁定子空间，自旋退相干率大大降低。首先，通过施加适度的磁场来实现异向自旋串扰的抑制。这导致两个稀释的和弱相互作用的旋转浴。第二，由于原子核之间的相互作用变弱，相互自旋翻转过程以较低的速率发生，这可以被视为噪声谱的高频部分的减少。因此，动态解耦协议表现出高性能。使用这种方法，作者能够保持20 ms以上的相干自旋叠加，与SiC中早期报道的值相比，这是一个多个数量级的改进。
One of the challenges in quantum information science is to achieve ultralong spin coherence in naturally grown solid-state systems. So far, isotope engineering is generally needed to suppress the main relaxation mechanism caused by the interaction with nuclear spins. The authors demonstrate here that this ambitious goal can be achieved in binary compounds with natural isotope abundance too. They attain a spin-locked subspace with a drastically reduced spin-decoherence rate through the combination of two effects. First, the suppression of heteronuclear spin cross-talk is achieved by applying a moderate magnetic field. This leads to two dilute and weakly interacting spin baths. Second, because the interaction between nuclei becomes weak, the mutual spin flip-flop processes occur at lower rate, which can be viewed as a reduction of the high-frequency part of the noise spectrum. As a result, dynamic decoupling protocols demonstrate high performance. Using this approach, the authors are able to preserve a coherent spin superposition above 20 ms, which is an improvement by more than one order of magnitude compared to the earlier reported value in SiC.