Estimating the error of an analog quantum simulator by additional measurements

Abstract

We study an analog quantum simulator coupled to a reservoir with a known spectral density. The reservoir perturbs the quantum simulation by causing decoherence. The simulator is used to measure an operator average, which cannot be calculated using any classical means. Since we cannot predict the result, it is difficult to estimate the effect of the environment. Especially, it is difficult to resolve whether the perturbation is small or if the actual result of the simulation is in fact very different from the ideal system we intend to study. Here, we show that in specific systems a measurement of additional correlators can be used to verify the reliability of the quantum simulation. The procedure only requires additional measurements on the quantum simulator itself. We demonstrate the method theoretically in the case of a single spin connected to a bosonic environment.

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Cited by in corpus (5)

• Finding the ground state of the Hubbard model by variational methods on a quantum computer with gate errors
• Effects of gate errors in digital quantum simulations of fermionic systems
• Reconstructing the ideal results of a perturbed analog quantum simulator
• Analyzing the spectral density of a perturbed analog quantum simulator using Keldysh formalism
• Stability of thermal equilibrium in long-range quantum systems