Unifying non-Markovian characterisation with an efficient and self-consistent framework

• URL: http://arxiv.org/abs/2312.08454v1
• Date: Wed, 13 Dec 2023 19:00:23 GMT
• Title: Unifying non-Markovian characterisation with an efficient and self-consistent framework
• Authors: Gregory A. L. White, Petar Jurcevic, Charles D. Hill, Kavan Modi
• Abstract summary: Nearly all quantum devices are plagued by noisy quantum and classical correlations at the level of the circuit. We establish a theoretical framework that uniformly incorporates and classifies all non-Markovian phenomena. We formulate an efficient reconstruction using network learning, allowing also for easy modularisation and simplification.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Noise on quantum devices is much more complex than it is commonly given credit. Far from usual models of decoherence, nearly all quantum devices are plagued both by a continuum of environments and temporal instabilities. These induce noisy quantum and classical correlations at the level of the circuit. The relevant spatiotemporal effects are difficult enough to understand, let alone combat. There is presently a lack of either scalable or complete methods to address the phenomena responsible for scrambling and loss of quantum information. Here, we make deep strides to remedy this problem. We establish a theoretical framework that uniformly incorporates and classifies all non-Markovian phenomena. Our framework is universal, assumes unknown control, and is written entirely in terms of experimentally accessible circuit-level quantities. We formulate an efficient reconstruction using tensor network learning, allowing also for easy modularisation and simplification based on the expected physics of the system. This is then demonstrated through both extensive numerical studies and experiments on IBM Quantum devices, estimating a comprehensive set of spacetime correlations. Finally, we conclude our analysis with applications thereof to the efficacy of control techniques to counteract these effects -- including noise-aware circuit compilation and optimised dynamical decoupling. We find significant improvements are possible in the diamond norm and average gate fidelity of arbitrary $SU(4)$ operations, as well as related decoupling improvements in contrast to off-the-shelf schemes.

Related papers

• Dynamical simulations of many-body quantum chaos on a quantum computer [3.731709137507907]
  We study a class of maximally chaotic circuits known as dual unitary circuits. We show that a superconducting quantum processor with 91 qubits is able to accurately simulate these correlators. We then probe dynamics beyond exact verification, by perturbing the circuits away from the dual unitary point.
  arXiv  Detail & Related papers  (2024-11-01T17:57:13Z)
• Many-time physics in practice: characterising and controlling non-Markovian quantum stochastic processes [0.0]
  We present a generalisation of quantum process tomography, called process tensor tomography (PTT) PTT establishes the ability to rigorously and systematically non-Markovian open quantum systems. We develop the framework of PTT, including experiment design, post-processing algorithms, and both simulated and near-term device demonstrations.
  arXiv  Detail & Related papers  (2024-05-08T20:34:53Z)
• Syncopated Dynamical Decoupling for Suppressing Crosstalk in Quantum Circuits [12.29963230632145]
  We study the use of dynamical decoupling in characterizing undesired two-qubit couplings and the underlying single-qubit decoherence. We develop a syncopated decoupling technique which protects against decoherence and selectively targets unwanted two-qubit interactions.
  arXiv  Detail & Related papers  (2024-03-12T17:18:35Z)
• Quantum error mitigation for Fourier moment computation [49.1574468325115]
  This paper focuses on the computation of Fourier moments within the context of a nuclear effective field theory on superconducting quantum hardware. The study integrates echo verification and noise renormalization into Hadamard tests using control reversal gates. The analysis, conducted using noise models, reveals a significant reduction in noise strength by two orders of magnitude.
  arXiv  Detail & Related papers  (2024-01-23T19:10:24Z)
• Quantum algorithms: A survey of applications and end-to-end complexities [90.05272647148196]
  The anticipated applications of quantum computers span across science and industry. We present a survey of several potential application areas of quantum algorithms. We outline the challenges and opportunities in each area in an "end-to-end" fashion.
  arXiv  Detail & Related papers  (2023-10-04T17:53:55Z)
• Matrix product channel: Variationally optimized quantum tensor network to mitigate noise and reduce errors for the variational quantum eigensolver [0.0]
  We develop a method to exploit the quantum-classical interface provided by informationally complete measurements. We argue that a hybrid strategy of using the quantum hardware together with the classical software outperforms a purely classical strategy. The algorithm can be applied as the final postprocessing step in the quantum hardware simulation of protein-ligand complexes in the context of drug design.
  arXiv  Detail & Related papers  (2022-12-20T13:03:48Z)
• Noisy Quantum Kernel Machines [58.09028887465797]
  An emerging class of quantum learning machines is that based on the paradigm of quantum kernels. We study how dissipation and decoherence affect their performance. We show that decoherence and dissipation can be seen as an implicit regularization for the quantum kernel machines.
  arXiv  Detail & Related papers  (2022-04-26T09:52:02Z)
• Quantum algorithms for quantum dynamics: A performance study on the spin-boson model [68.8204255655161]
  Quantum algorithms for quantum dynamics simulations are traditionally based on implementing a Trotter-approximation of the time-evolution operator. variational quantum algorithms have become an indispensable alternative, enabling small-scale simulations on present-day hardware. We show that, despite providing a clear reduction of quantum gate cost, the variational method in its current implementation is unlikely to lead to a quantum advantage.
  arXiv  Detail & Related papers  (2021-08-09T18:00:05Z)
• Realization of arbitrary doubly-controlled quantum phase gates [62.997667081978825]
  We introduce a high-fidelity gate set inspired by a proposal for near-term quantum advantage in optimization problems. By orchestrating coherent, multi-level control over three transmon qutrits, we synthesize a family of deterministic, continuous-angle quantum phase gates acting in the natural three-qubit computational basis.
  arXiv  Detail & Related papers  (2021-08-03T17:49:09Z)
• Error mitigation and quantum-assisted simulation in the error corrected regime [77.34726150561087]
  A standard approach to quantum computing is based on the idea of promoting a classically simulable and fault-tolerant set of operations. We show how the addition of noisy magic resources allows one to boost classical quasiprobability simulations of a quantum circuit.
  arXiv  Detail & Related papers  (2021-03-12T20:58:41Z)
• Demonstration of non-Markovian process characterisation and control on a quantum processor [0.0]
  Non-Markovian noise poses a serious challenge to the progression of quantum technology. We develop a framework for characterising non-Markovian dynamics in quantum systems. Our results show this characterisation technique leads to superior quantum control and extension of coherence time.
  arXiv  Detail & Related papers  (2020-04-29T08:29:29Z)

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.