Speaker
Description
Trapped ions are one of the most promising platforms for a large-scale quantum computer. For this purpose, they are usually cooled to temperatures at millikelvin range, where they form Coulomb crystals. A trapped-ion quantum computer based on a linear crystal of 24 ions has been previously demonstrated [1]. However, the length of a linear crystal creates increasing challenges for production of a computer with a higher number of ions [2]. One solution could be a platform of several traps and transport of ions between them by QCCD architecture [3], but this approach requires complicated electric circuitry. A trap array without ion transport between traps has been also suggested [4], but it has a drawback of low coupling rates between the ions. An alternative idea is to confine the ions to a single multidimensional crystal in a point Paul trap. Unfortunately, we are not aware of any extensive study for defining the vibrational modes of ion crystals in a realistic point Paul trap design.
We present a method for finding the vibrational modes based on ion trajectories from FEM simulations and their frequency analysis. The simulations have been made by using the oscillating electric field of our coaxial Paul trap, also solved by FEM. We successfully test the method for finding in-plane vibrational modes for crystals from one to seven ions and comparing it with reference data [5]. We also evaluate the melting points of such crystals, in order to prevent geometric changes. The results are expected to contribute to the future development of qubits in our laboratory, as well as offer guidelines for comparable work with other Paul traps.
References
[1] I. Pogorelov et al., PRX Quantum 2, 020343, (2021)
[2] P. Murali et al., IEEE Micro 40, 73–80, (2020)
[3] J. M. Pino et al., Nature 592, 209–213, (2021)
[4] P. C. Holz et al., Adv. Quantum Technol. 3, 2000031, (2020)
[5] K. Nelissen et al., Phys. Rev. E 73, 016607, (2006)
