Heisenberg-limited calibration of entangling gates with robust phase estimation

• URL: http://arxiv.org/abs/2502.06698v1
• Date: Mon, 10 Feb 2025 17:21:42 GMT
• Title: Heisenberg-limited calibration of entangling gates with robust phase estimation
• Authors: Kenneth Rudinger, J. P. Marceaux, Akel Hashim, David I. Santiago, Irfan Siddiqi, Kevin C. Young,
• Abstract summary: We show that robust phase estimation can enable high-precision, Heisenberg-limited estimates of coherent errors in multi-qubit gates. We experimentally demonstrate our calibration protocols by improving the operation of a two-qubit controlled-Z gate on a superconducting processor.
• Score: 0.0
• License:
• Abstract: The calibration of high-quality two-qubit entangling gates is an essential component in engineering large-scale, fault-tolerant quantum computers. However, many standard calibration techniques are based on randomized circuits that are only quadratically sensitive to calibration errors. As a result, these approaches are inefficient, requiring many experimental shots to achieve acceptable performance. In this work, we demonstrate that robust phase estimation can enable high-precision, Heisenberg-limited estimates of coherent errors in multi-qubit gates. Equipped with an efficient estimator, the calibration problem may be reduced to a simple optimization loop that minimizes the estimated coherent error. We experimentally demonstrate our calibration protocols by improving the operation of a two-qubit controlled-Z gate on a superconducting processor, and we validate the improved performance with gate set tomography. Our methods are applicable to gates in other quantum hardware platforms such as ion traps and neutral atoms, and on other multi-qubit gates, such as CNOT or iSWAP.

Related papers

• High-precision pulse calibration of tunable couplers for high-fidelity two-qubit gates in superconducting quantum processors [25.085187014541432]
  We introduce and experimentally validate a novel pulse calibration scheme that exploits the strong coupling between qubits and couplers. Our method directly measures the short-time and long-time step responses of the coupler flux pulse transient. We demonstrate the efficacy of our method through the implementation of diabatic CZ and iSWAP gates with fidelities of $99.61pm0.04%$ and $99.82pm0.02%$, respectively.
  arXiv  Detail & Related papers  (2024-10-19T08:55:14Z)
• In situ mixer calibration for superconducting quantum circuits [21.239311757123467]
  We introduce an in situ calibration technique and outcome-focused mixer calibration scheme using superconducting qubits. We experimentally validate the efficacy of this technique by benchmarking single-qubit gate fidelity and qubit coherence time.
  arXiv  Detail & Related papers  (2024-08-21T14:49:39Z)
• Fast Flux-Activated Leakage Reduction for Superconducting Quantum Circuits [84.60542868688235]
  leakage out of the computational subspace arising from the multi-level structure of qubit implementations. We present a resource-efficient universal leakage reduction unit for superconducting qubits using parametric flux modulation. We demonstrate that using the leakage reduction unit in repeated weight-two stabilizer measurements reduces the total number of detected errors in a scalable fashion.
  arXiv  Detail & Related papers  (2023-09-13T16:21:32Z)
• Hamiltonian Phase Error in Resonantly Driven CNOT Gate Above the Fault-Tolerant Threshold [0.0]
  electron spin qubits are a promising platform for scalable quantum processors. A full-fledged quantum computer will need quantum error correction, which requires high-fidelity quantum gates. We demonstrate a simple yet reliable calibration procedure for a high-fidelity controlled-rotation gate in an exchange-always-on Silicon quantum processor.
  arXiv  Detail & Related papers  (2023-07-18T07:44:00Z)
• Fast Quantum Calibration using Bayesian Optimization with State Parameter Estimator for Non-Markovian Environment [11.710177724383954]
  We propose a real-time optimal estimator of qubit states, which utilizes weak measurements and Bayesian optimization to find the optimal control pulses for gate design. Our numerical results demonstrate a significant reduction in the calibration process, obtaining a high gate fidelity.
  arXiv  Detail & Related papers  (2022-05-25T17:31:15Z)
• Measuring NISQ Gate-Based Qubit Stability Using a 1+1 Field Theory and Cycle Benchmarking [50.8020641352841]
  We study coherent errors on a quantum hardware platform using a transverse field Ising model Hamiltonian as a sample user application. We identify inter-day and intra-day qubit calibration drift and the impacts of quantum circuit placement on groups of qubits in different physical locations on the processor. This paper also discusses how these measurements can provide a better understanding of these types of errors and how they may improve efforts to validate the accuracy of quantum computations.
  arXiv  Detail & Related papers  (2022-01-08T23:12:55Z)
• Analytical and experimental study of center line miscalibrations in M\o lmer-S\o rensen gates [51.93099889384597]
  We study a systematic perturbative expansion in miscalibrated parameters of the Molmer-Sorensen entangling gate. We compute the gate evolution operator which allows us to obtain relevant key properties. We verify the predictions from our model by benchmarking them against measurements in a trapped-ion quantum processor.
  arXiv  Detail & Related papers  (2021-12-10T10:56:16Z)
• Fault-tolerant parity readout on a shuttling-based trapped-ion quantum computer [64.47265213752996]
  We experimentally demonstrate a fault-tolerant weight-4 parity check measurement scheme. We achieve a flag-conditioned parity measurement single-shot fidelity of 93.2(2)%. The scheme is an essential building block in a broad class of stabilizer quantum error correction protocols.
  arXiv  Detail & Related papers  (2021-07-13T20:08:04Z)
• Crosstalk Suppression for Fault-tolerant Quantum Error Correction with Trapped Ions [62.997667081978825]
  We present a study of crosstalk errors in a quantum-computing architecture based on a single string of ions confined by a radio-frequency trap, and manipulated by individually-addressed laser beams. This type of errors affects spectator qubits that, ideally, should remain unaltered during the application of single- and two-qubit quantum gates addressed at a different set of active qubits. We microscopically model crosstalk errors from first principles and present a detailed study showing the importance of using a coherent vs incoherent error modelling and, moreover, discuss strategies to actively suppress this crosstalk at the gate level.
  arXiv  Detail & Related papers  (2020-12-21T14:20:40Z)
• Efficient and robust certification of genuine multipartite entanglement in noisy quantum error correction circuits [58.720142291102135]
  We introduce a conditional witnessing technique to certify genuine multipartite entanglement (GME) We prove that the detection of entanglement in a linear number of bipartitions by a number of measurements scales linearly, suffices to certify GME. We apply our method to the noisy readout of stabilizer operators of the distance-three topological color code and its flag-based fault-tolerant version.
  arXiv  Detail & Related papers  (2020-10-06T18:00:07Z)
• Integrated tool-set for Control, Calibration and Characterization of quantum devices applied to superconducting qubits [0.5269923665485903]
  We present a methodology to find a quantitatively accurate system model, high-fidelity gates and an approximate error budget. We derive a coherence limited cross-resonance gate that achieves 99.6% fidelity without need for calibration.
  arXiv  Detail & Related papers  (2020-09-21T13:38:45Z)

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.