S38.00001. Variational quantum control for single- and two-qubit transmon gates
Presented by: Juan José García Ripoll
Transmon are among the most successful qubits in the superconducting world, enabling the largest gate-based quantum computations to-date. In this talk I will present a new set of techniques to design single-qubit and two-qubit gates for transmon qubits, which can be used to tune qubit frequencies, implement direct or cavity mediated CZ interactions , and √SWAP gates with tuneable couplers. The technique is based on variational estimates of the transmon qubit state dynamics, and provides semi-analytical controls that can be further tuned to develop more robust protocols. With minor efforts, methods provide various orders of magnitude improvement in fidelity over earlier techniques based on fast-quasi-adiabatic passages or conventional square or segmented pulses, as used in current experiments.  L. DiCarlo et al, Nature 467, 574 (2010)  R. Barends et al. Nature 508, 500 (2014)  Y. Chen et al. Physical Review Letters 113,220502 (2014) This work has been supported by funding from project PGC2018-094792-B-I00 (MCIU/AEI/FEDER, UE) and CAM/FEDER Project No. S2018/TCS-4342 (QUITEMAD-CM).
- Andrés Ruiz Chamorro
- Erik Torrontegui
- Juan José García-Ripoll