Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2010 Dec 31;105(26):266808. doi: 10.1103/PhysRevLett.105.266808. Epub 2010 Dec 30.
We experimentally demonstrate coherence recovery of singlet-triplet superpositions by interlacing qubit rotations between Carr-Purcell (CP) echo sequences. We then compare the performance of Hahn, CP, concatenated dynamical decoupling (CDD), and Uhrig dynamical decoupling for singlet recovery. In the present case, where gate noise and drift combined with spatially varying hyperfine coupling contribute significantly to dephasing, and pulses have limited bandwidth, CP and CDD yield comparable results, with T(2)∼80 μs.
我们通过在 Carr-Purcell（CP）回波序列之间交错量子比特旋转，实验证明了单重态-三重态叠加的相干恢复。然后，我们比较了 Hahn、CP、串联动态解耦（CDD）和 Uhrig 动态解耦在单重态恢复方面的性能。在本案例中，门噪声和漂移与空间变化的超精细耦合相结合会显著导致退相，且脉冲带宽有限，CP 和 CDD 的结果相当，T(2)∼80 μs。
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