Scalable quantum computation with fast gates in two-dimensional microtrap arrays of trapped ions

Abstract

We theoretically investigate the use of fast pulsed two-qubit gates for trapped ion quantum computing in a two-dimensional microtrap architecture. In one dimension, such fast gates are optimal when employed between nearest neighbors, and we examine the generalization to a two-dimensional geometry. We demonstrate that fast pulsed gates are capable of implementing high-fidelity entangling operations between ions in neighboring traps faster than the trapping period, with experimentally demonstrated laser repetition rates. Notably, we find that without increasing the gate duration high-fidelity gates are achievable even in large arrays with hundreds of ions. To demonstrate the usefulness of this proposal, we investigate the application of these gates to the digital simulation of a 40-mode Fermi-Hubbard model. This also demonstrates why shorter chains of gates required to connect arbitrary pairs of ions make this geometry well suited for large-scale computation.

Ultra-fast two-qubit ion gate using sequences of resonant pulses

“…A second, more pressing question, concerns the parallelizability and scalability of our pulsed schemes. Recent works have addressed theoretically [21,46,47] and demonstrated experimentally [48,49] the simultaneous implementation of arbitrary twoqubit gates among a subset or all pairs of K ions in a trap. We can use our two-step protocol to perform this task with significant speed ups.…”

Digital quantum simulation of an extended Agassi model: Using machine learning to disentangle its phase-diagram

“…Nevertheless, the estimations seem to agree that this proposal should be achievable in the near future as a good progress is being made in scaling trapped ion systems to the hundreds or thousands of qubits [20,21]. Some approaches with promising results are the implementation of high fidelity fast gates [22,23] and two-dimensional ion traps, since the fidelities in each dimension are independent from one another [24]. The use of a higher-order Trotter expansion would also help 064322-3 reducing the required number of Trotter steps for an accurate approximation [15].…”

A digital quantum simulation of an extended Agassi model assisted by machine learning

“…Nevertheless, the estimations seem to agree that this proposal should be achievable in the near future as a good progress is being made in scaling trapped ion systems to the hundreds or thousands of qubits [20,21]. Some approaches with promising results are the implementation of high fidelity fast gates [22,23] and two dimensional ion traps, since the fidelities in each dimension are independent from one another [24]. The use of a higher-order Trotter expansion would also help reducing the required number of Trotter steps for an accurate approximation [15].…”

“…Appendix A: Decomposition of the Hamiltonian in σ x , σ y , and σ z Each term is denoted as H i,j where H i are the Hamiltonian terms H 1 to H 6 from Eqs. (18)(19)(20)(21)(22)(23)(24) and j denotes each of the terms that arise from each H i :…”