Predicting Non-Markovian Superconducting-Qubit Dynamics from Tomographic Reconstruction

Zhang, Haimeng; Pokharel, Bibek; Levenson-Falk, E. M.; Lidar, Daniel A.

doi:10.1103/physrevapplied.17.054018

Cited by 16 publications

(12 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are various metrics that can be used to assess the accuracy of an approximate open quantum systems evolution. One approach is to consider the performance of the approximation only for a small, specific subset of initial states [33]. A more complete approach is to try to compare the full structure of the exact and approximate evolution maps (e.g., Ref.…”

Section: Benchmarking the Plme Against Numerically-exact Resultsmentioning

confidence: 99%

Simple master equations for describing driven systems subject to classical non-Markovian noise

Groszkowski

Seif

Koch

et al. 2023

Quantum

View full text Add to dashboard Cite

Driven quantum systems subject to non-Markovian noise are typically difficult to model even if the noise is classical. We present a systematic method based on generalized cumulant expansions for deriving a time-local master equation for such systems. This master equation has an intuitive form that directly parallels a standard Lindblad equation, but contains several surprising features: the combination of driving and non-Markovianity results in effective time-dependent dephasing rates that can be negative, and the noise can generate Hamiltonian renormalizations even though it is classical. We analyze in detail the highly relevant case of a Rabi-driven qubit subject to various kinds of non-Markovian noise including 1/f fluctuations, finding an excellent agreement between our master equation and numerically-exact simulations over relevant timescales. The approach outlined here is more accurate than commonly employed phenomenological master equations which ignore the interplay between driving and noise.

show abstract

Section: Benchmarking the Plme Against Numerically-exact Resultsmentioning

confidence: 99%

Simple master equations for describing driven systems subject to classical non-Markovian noise

Groszkowski

Seif

Koch

et al. 2023

Quantum

View full text Add to dashboard Cite

show abstract

“…Although the presence of multi-frequency oscillations and damped purity oscillations are two signatures of non-Markovian noise in single qubit systems, various other metrics have been proposed to quantify non-Markovian noise [20,30,31]. For example, the increase in the distinguishability of two different quantum states over time can quantify non-Markovianity [31].…”

Section: Non-markovian Noise and Its Signaturesmentioning

confidence: 99%

“…This 'locks' the qubit in a specific state even in the presence of external perturbations. On the other extreme, significant non-Markovian effects have been shown to occur in the dynamics of idle qubits prepared in the equator of the Bloch sphere [20].…”

Section: Noise Characterisation Circuitsmentioning

confidence: 99%

Modelling non-Markovian noise in driven superconducting qubits

Agarwal,

Lindoy,

Lall

et al. 2024

Quantum Sci. Technol.

View full text Add to dashboard Cite

Non-Markovian noise can be a significant source of errors in superconducting qubits. We develop gate sequences utilising mirrored pseudoidentities that allow us to characterise and model the effects of non-Markovian noise on both idle and driven qubits. We compare three approaches to modelling the observed noise: (i) a Markovian noise model, (ii) a model including interactions with a two-level system (TLS), (iii) a model utilising the post Markovian master equation (PMME), which we show to be equivalent to the qubit-TLS model in certain regimes. When running our noise characterisation circuits on a superconducting qubit device we find that purely Markovian noise models cannot reproduce the experimental data. Our model based on a qubit-TLS interaction, on the other hand, is able to closely capture the observed experimental behaviour for both idle and driven qubits. We investigate the stability of the noise properties of the hardware over time, and find that the parameter governing the qubit-TLS interaction strength fluctuates significantly even over short time-scales of a few minutes. Finally, we evaluate the changes in the noise parameters when increasing the qubit drive pulse amplitude. We find that although the hardware noise parameters fluctuate significantly over different days, their drive pulse induced relative variation is rather well defined within computed uncertainties: both the phase error and the qubit-TLS interaction strength change significantly with the pulse strength, with the phase error changing quadratically with the amplitude of the applied pulse. Since our noise model can closely describe the behaviour of idle and driven qubits, it is ideally suited to be used in the development of quantum error mitigation and correction methods.

show abstract

“…Quantum information science, with its rapid growth over the past years, has been crucial in providing insights in the foundations of quantum mechanics, while allowing the development of quantum technologies. In fact, controlling a quantum device would be an impossible task without a deep understanding of the interplay between systems and their surrounding environments [1,2,3,4]. This is indeed one of the main goals in the analysis of Open Quantum Systems (OQS): to study the dynamics of quantum systems interacting with their equally quantum environments [5,6,7,8] One of the main features OQS, at variance with their isolated counterparts, is that they inherently exhibit memory effects, due to the dynamical generation of entanglement between the principal system and its environment.…”

Section: Introductionmentioning

confidence: 99%

Nature and origin of the operators entering the master equation of an open quantum system

Spaventa,

Verrucchi

2022

Preprint

View full text Add to dashboard Cite

By exploiting the peculiarities of a recently introduced formalism for describing open quantum systems (the Parametric Representation with Environmental Coherent States) we derive an equation of motion for the reduced density operator of an open quantum system that has the same structure of the celebrated Gorini-Kossakowski-Sudarshan-Lindblad equation, but holds regardless of markovianity being assumed. The operators in our result have explicit expressions in terms of the Hamiltonian describing the interactions with the environment, and can be computed once a specific model is considered. We find that, instead of a single set of Lindblad operators, in the general (non-markovian) case there one set of Lindblad-like operators for each and every point of a symplectic manifold associated to the environment. This intricacy disappears under some assumptions (which are related to markovianity and the classical limit of the environment), under which it is possible to recover the usual master-equation formalism. Finally, we find such Lindblad-like operators for two different models of a qubit in a bosonic environment, and show that in the classical limit of the environment their renown master equations are recovered.

show abstract

Predicting Non-Markovian Superconducting-Qubit Dynamics from Tomographic Reconstruction

Cited by 16 publications

References 48 publications

Simple master equations for describing driven systems subject to classical non-Markovian noise

Simple master equations for describing driven systems subject to classical non-Markovian noise

Modelling non-Markovian noise in driven superconducting qubits

Nature and origin of the operators entering the master equation of an open quantum system

Contact Info

Product

Resources

About