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Open Systems with Error Bounds: Spin-Boson Model with Spectral Density Variations.

F Mascherpa1, A Smirne1, S F Huelga1

  • 1Institut für Theoretische Physik, Universität Ulm, Ulm D-89069, Germany.

Physical Review Letters
|March 25, 2017
PubMed
Summary
This summary is machine-generated.

Uncertainty in spectral densities for open quantum systems can affect predictions. This study provides error bounds for the spin-boson model, improving theoretical accuracy.

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Area of Science:

  • Quantum mechanics
  • Open quantum systems
  • Theoretical physics

Background:

  • Spectral density is crucial for modeling environmental effects in open quantum systems.
  • In many models, spectral density is not directly computable and must be inferred or fitted, leading to uncertainty.
  • This uncertainty questions the reliability of theoretical predictions based on spectral density.

Purpose of the Study:

  • To develop methods for quantifying the impact of spectral density uncertainty on theoretical predictions.
  • To establish error bounds for expectation values in the spin-boson model.
  • To assess the accuracy of approximations in quantum dynamics simulations.

Main Methods:

  • Focusing on the spin-boson model as a representative open quantum system.
  • Deriving two distinct error bounds based on variations in the spectral density.
  • Identifying conditions under which the most stringent error bound is applicable.

Main Results:

  • Two error bounds were derived for predicted expectation values in the spin-boson model.
  • A sufficient condition for the application of the stronger error bound was established.
  • The derived bounds were applied to quantify errors in the hierarchical equations of motion method.

Conclusions:

  • The study provides a rigorous way to assess the impact of spectral density uncertainty.
  • The derived error bounds enhance the reliability of theoretical predictions in open quantum systems.
  • This work offers a method to evaluate approximations in quantum dynamics simulations, particularly for the spin-boson model.