Optimised fast gates for quantum computing with trapped ions

Abstract

We present an efficient approach to optimising pulse sequences for implementing fast entangling two-qubit gates on trapped ion quantum information processors. We employ a two-phase procedure for optimising gate fidelity, which we demonstrate for multi-ion systems in linear Paul trap and microtrap architectures. The first phase involves a global optimisation over a computationally inexpensive cost function constructed under strong approximations of the gate dynamics. The second phase involves local optimisations that utilise a more precise ODE description of the gate dynamics, which captures the non-linearity of the Coulomb interaction and the effects of finite laser repetition rate. We propose two novel gate schemes that are compatible with this approach, and we demonstrate that they outperform existing schemes in terms of achievable gate speed and fidelity for feasible laser repetition rates. In optimising sub-microsecond gates in microtrap architectures, the proposed schemes achieve orders of magnitude higher fidelities than previous proposals. Finally, we investigate the impact of pulse imperfections on gate fidelity and evaluate error bounds for a range of gate speeds.

arXiv comment13 pages, 7 figures, 1 table

References in corpus (44)

• Quantum Computing
• Review article: Linear optical quantum computing
• Quantum state engineering with Josephson-junction devices
• Experimental issues in coherent quantum-state manipulation of trapped atomic ions
• Quantum computing with trapped ions
• Quantum computation with ions in thermal motion
• Multi-particle entanglement of hot trapped ions
• Entanglement and quantum computation with ions in thermal motion
• Demonstration of a small programmable quantum computer with atomic qubits
• High-fidelity quantum logic gates using trapped-ion hyperfine qubits
• High-fidelity two-qubit quantum logic gates using trapped calcium-43 ions
• Training Schrödinger's cat: quantum optimal control
• High-fidelity preparation, gates, memory and readout of a trapped-ion quantum bit
• High-Fidelity Universal Gate Set for ${}^9$Be${}^{+}$ Ion Qubits
• Quantum chemistry calculations on a trapped-ion quantum simulator
• Prospects for Spin-Based Quantum Computing
• Experimental Quantum Computations on a Topologically Encoded Qubit
• Observation of Entangled States of a Fully Controlled 20-Qubit System
• High-fidelity readout of trapped-ion qubits
• The Ion Trap Quantum Information Processor
• Fast and robust two-qubit gates for scalable ion trap quantum computing
• Fast quantum logic gates with trapped-ion qubits
• XMDS2: Fast, scalable simulation of coupled stochastic partial differential equations
• Review of Decoherence Free Subspaces, Noiseless Subsystems, and Dynamical Decoupling
• Phase Control of Trapped Ion Quantum Gates
• Ultrafast Gates for Single Atomic Qubits
• Fast quantum gates for cold trapped ions
• How to realize a universal quantum gate with trapped ions
• EIT ground-state cooling of long ion strings
• Arbitrary-speed quantum gates within large ion crystals through minimum control of laser beams
• Scaling Ion Trap Quantum Computation through Fast Quantum Gates
• Coherent control of trapped ions using off-resonant lasers
• A trapped-ion based quantum byte with $10^{-5}$ next-neighbour cross-talk
• Pulsed force sequences for fast phase-insensitive quantum gates in trapped ions
• Operation of a planar-electrode ion-trap array with adjustable RF electrodes
• Scaling Trapped Ion Quantum Computers Using Fast Gates and Microtraps
• Fast gates for ion traps by splitting laser pulses
• The distribution of quantum fidelities
• Trapped ion scaling with pulsed fast gates
• A Study on Fast Gates for Large-Scale Quantum Simulation with Trapped Ions
• Ultrafast coherent excitation of a Ca${}^{+}$ ion
• Ultrafast, high repetition rate, ultraviolet, fiber based laser source: application towards Yb+ fast quantum-logic
• Micromotion-Enhanced Fast Entangling Gates For Trapped Ion Quantum Computing
• Stability thresholds and calculation techniques for fast entangling gates on trapped ions

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