Robert Throckmorton (CMTC and JQI)
April 21, 2017
We present new composite pulse sequences for performing arbitrary rotations in singlet-triplet qubits that are faster than existing sequences. We consider two sequences for performing a z rotation, one that generalizes the Hadamard-x-Hadamard sequence, and another that generalizes a sequence by Guy Ramon (G. Ramon, Phys. Rev. B 84, 155329 (2011)). We determine the time required to perform each sequence, and find that our "generalized Hadamard-x-Hadamard" sequence can always be made faster than the "generalized Ramon sequence". We then present similar sequences for performing x rotations, one that generalizes the Hadamard-z-Hadamard sequence and another that is based on Ramon's z rotation sequence. In this case, we find that the "Ramon-like" sequence is faster. We also present sequences for performing other rotations. We then find versions of these sequences dynamically corrected for noise-induced errors using SUPCODE (X. Wang et. al., PRA 89, 022310 (2014)).
Reference: C. Zhang, RET, X-C. Yang, X. Wang, E. Barnes, and S. Das Sarma, arXiv:1701.03796 (submitted to PRL), plus currently unpublished work.