Experimental realization of nonadiabatic geometric gates with a superconducting Xmon qubit

Research paper by P. Z. Zhao, Zhangjingzi Dong, Zhenxing Zhang, Guoping Guo, D. M. Tong, Yi Yin

Indexed on: 11 Dec '20Published on: 22 Sep '19Published in: arXiv - Quantum Physics


Geometric phases are only dependent on evolution paths but independent of evolution details so that they own some intrinsic noise-resilience features. Based on different geometric phases, various quantum gates have been proposed, such as nonadiabatic geometric gates based on nonadiabatic Abelian geometric phases and nonadiabatic holonomic gates based on nonadiabatic non-Abelian geometric phases. Up to now, nonadiabatic holonomic one-qubit gates have been experimentally demonstrated with the supercondunting transmon, where three lowest levels with cascaded configuration are all applied in the operation. However, the second excited states of transmons have relatively short coherence time, which results in a lessened fidelity of quantum gates. Here, we experimentally realize Abelian-geometric-phase-based nonadiabatic geometric one-qubit gates with a superconducting Xmon qubit. The realization is performed on two lowest levels of an Xmon qubit and thus avoids the influence from the short coherence time of the second excited state. The experimental result indicates that the average fidelities of single-qubit gates can be up to 99.6% and 99.7% characterized by quantum process tomography and randomized benchmarking, respectively.