Abstract: Scalable quantum computation has the potential to solve certain problems far more efficiently than classical computation. Trapped ions offer a promising platform for scalable quantum computation. However, as the system size scales up, both computational speed and gate fidelity can deteriorate.

       In this talk, I will present two Hamiltonian engineering approaches to enhance the speed and fidelity of quantum gates in trapped-ion systems, thereby addressing key challenges associated with scaling. The first approach employs parametric amplification of the ions’ motion to enhance coherent interactions [1, 2]. The second approach uses amplitude modulation of laser pulses that couple the ions’ internal qubit states and their collective motional modes, enabling optimal control of the system [3].

       To demonstrate the effectiveness of these methods, I will present examples showing significant improvements in the speed and the fidelity of two-qubit gates. These results open new avenues towards scalable trapped-ion quantum computing and have direct relevance to a wide range of other physical platforms.

References:

1. Wenchao Ge, B. Sawyer, J. Britton, K. Jacobs, J. Bollinger, M. Foss-Feig, “Trapped Ion Quantum Information Processing with Squeezed Phonons”, Phys. Rev. Lett. 122, 030501 (2019)
2. SC Burd, Raghavendra Srinivas, HM Knaack, Wenchao Ge, AC Wilson, DJ Wineland, Dietrich Leibfried, JJ Bollinger, DTC Allcock, DH Slichter, “Quantum amplification of boson-mediated interactions”, Nature Physics 17, 898 (2021)
3. Luke Ellert-Beck, and Wenchao Ge, “Power-optimized amplitude modulation for robust trapped-ion entangling gates: a study of gate-timing errors”, Phys. Rev. A 111, 062422 (2025)