Batch Optimization of Frequency-Modulated Pulses for Robust Two-qubit Gates in Ion Chains

• URL: http://arxiv.org/abs/2104.06887v2
• Date: Mon, 20 Dec 2021 16:38:03 GMT
• Title: Batch Optimization of Frequency-Modulated Pulses for Robust Two-qubit Gates in Ion Chains
• Authors: Mingyu Kang, Qiyao Liang, Bichen Zhang, Shilin Huang, Ye Wang, Chao Fang, Jungsang Kim, Kenneth R. Brown
• Abstract summary: Two-qubit gates in trapped-ion quantum computers are generated by applying spin-dependent forces that temporarily entangle the internal state of the ion with its motion. Laser pulses are carefully designed to generate a maximally entangling gate between the ions while minimizing any residual entanglement between the motion and the ion. We improve the robustness of frequency-modulated Molmer-Sorensen gates to motional mode-frequency offsets by optimizing the average performance over a range of systematic errors.
• Score: 3.0916705331600047
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Two-qubit gates in trapped-ion quantum computers are generated by applying spin-dependent forces that temporarily entangle the internal state of the ion with its motion. Laser pulses are carefully designed to generate a maximally entangling gate between the ions while minimizing any residual entanglement between the motion and the ion. The quality of the gates suffers when the actual experimental parameters differ from the ideal case. Here, we improve the robustness of frequency-modulated M{\o}lmer-S{\o}rensen gates to motional mode-frequency offsets by optimizing the average performance over a range of systematic errors using batch optimization. We then compare this method with frequency-modulated gates optimized for ideal parameters that include an analytic robustness condition. Numerical simulations show good performance up to 12 ions, and the method is experimentally demonstrated on a two-ion chain.

Related papers

• High-performance conditional-driving gate for Kerr parametric oscillator qubits [0.0]
  We show that an AC-Zeeman shift due to the flux pulse for the gate operation largely affects the gate performance. We propose a method to cancel this undesirable effect. We numerically demonstrate a conditional-driving gate with average fidelity exceeding 99.9$%$ twice faster than that without the proposed method.
  arXiv  Detail & Related papers  (2024-10-01T09:58:52Z)
• Bespoke Pulse Design for Robust Rapid Two-Qubit Gates with Trapped Ions [0.0]
  Two-qubit gates with addressed Raman beams within a linear trapped-ion chain by a quantum master equation (QME) QME incorporates the single-ion two-photon effective Rabi frequency, Autler-Townes and vibrational Bloch-Siegert energy shifts, off-resonant transitions, Raman and Rayleigh scattering, laser-power fluctuations, motional heating, cross-Kerr phonon coupling, laser, asymmetric addressing beams, with no fitting parameters. Our robust quantum control delivers rapid high-quality two-qubit gates in long ion chains, enabling scalable quantum computing with trapped ions.
  arXiv  Detail & Related papers  (2022-12-01T18:06:44Z)
• Angle-robust Two-Qubit Gates in a Linear Ion Crystal [2.1368199320952286]
  Two-qubit entangling gates are generated by applying spin-dependent force which uses phonons to mediate interaction between the internal states of the ions. To maintain high-fidelity two-qubit gates under fluctuating experimental parameters, robust pulse-design methods are applied. We experimentally measure the performance of the designed gates and see an improvement on both gate fidelity and gate performance under uniform mode frequency offsets.
  arXiv  Detail & Related papers  (2022-10-10T16:24:18Z)
• Fast Ion Gates Outside the Lamb-Dicke Regime by Robust Quantum Optimal Control [16.769083043152627]
  We present a quantum optimal control framework for implementing fast entangling gates on ion-trap quantum processors. The framework leverages tailored laser pulses to drive the multiple vibrational sidebands of the ions to create phonon-mediated entangling gates. Our approach represents a step in speeding up quantum gates to achieve larger quantum circuits for quantum computation and simulation.
  arXiv  Detail & Related papers  (2022-09-20T11:14:00Z)
• Robustness of a universal gate set implementation in transmon systems via Chopped Random Basis optimal control [50.591267188664666]
  We numerically study the implementation of a universal two-qubit gate set, composed of CNOT, Hadamard, phase and $pi/8$ gates, for transmon-based systems. The control signals to implement such gates are obtained using the Chopped Random Basis optimal control technique, with a target gate infidelity of $10-2$.
  arXiv  Detail & Related papers  (2022-07-27T10:55:15Z)
• Accurate methods for the analysis of strong-drive effects in parametric gates [94.70553167084388]
  We show how to efficiently extract gate parameters using exact numerics and a perturbative analytical approach. We identify optimal regimes of operation for different types of gates including $i$SWAP, controlled-Z, and CNOT.
  arXiv  Detail & Related papers  (2021-07-06T02:02:54Z)
• Fast and differentiable simulation of driven quantum systems [58.720142291102135]
  We introduce a semi-analytic method based on the Dyson expansion that allows us to time-evolve driven quantum systems much faster than standard numerical methods. We show results of the optimization of a two-qubit gate using transmon qubits in the circuit QED architecture.
  arXiv  Detail & Related papers  (2020-12-16T21:43:38Z)
• Direct Optimal Control Approach to Laser-Driven Quantum Particle Dynamics [77.34726150561087]
  We propose direct optimal control as a robust and flexible alternative to indirect control theory. The method is illustrated for the case of laser-driven wavepacket dynamics in a bistable potential.
  arXiv  Detail & Related papers  (2020-10-08T07:59:29Z)
• Hessian-Free High-Resolution Nesterov Acceleration for Sampling [55.498092486970364]
  Nesterov's Accelerated Gradient (NAG) for optimization has better performance than its continuous time limit (noiseless kinetic Langevin) when a finite step-size is employed. This work explores the sampling counterpart of this phenonemon and proposes a diffusion process, whose discretizations can yield accelerated gradient-based MCMC methods.
  arXiv  Detail & Related papers  (2020-06-16T15:07:37Z)
• Scalable quantum computation with fast gates in two-dimensional microtrap arrays of trapped ions [68.8204255655161]
  We investigate the use of fast pulsed two-qubit gates for trapped ion quantum computing in a two-dimensional microtrap architecture. We demonstrate that fast pulsed gates are capable of implementing high-fidelity entangling operations between ions in neighbouring traps faster than the trapping period.
  arXiv  Detail & Related papers  (2020-05-01T13:18:22Z)
• Numeric optimization for configurable, parallel, error-robust entangling gates in large ion registers [0.0]
  We study a class of entangling gates for trapped atomic ions and demonstrate the use of numeric optimization techniques to create a wide range of fast, error-robust gate constructions. Our approach introduces a framework for numeric optimization using individually addressed, amplitude and phase modulated controls targeting maximally and partially entangling operations on ion pairs, complete multi-ion registers, multi-ion subsets of large registers, and parallel operations within a single register.
  arXiv  Detail & Related papers  (2020-05-01T13:17:59Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.