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Related Experiment Video

Updated: Sep 18, 2025

Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source

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Published on: April 4, 2017

Intrinsic and Measured Information in Separable Quantum Processes.

David Gier¹, James P Crutchfield¹

¹Complexity Sciences Center and Physics and Astronomy Department, University of California at Davis, One Shields Avenue, Davis, CA 95616, USA.

Entropy (Basel, Switzerland)

|June 26, 2025

Summary

This summary is machine-generated.

Researchers developed methods to understand quantum information sources by analyzing their classical outputs. This allows for synchronization with the source

Keywords:

Shannon entropy rate adaptive measurement classical information theory computational mechanics excess entropy hidden Markov models information source measurement mutual information non-Markovian process positive operator-valued measure quantum information theory quantum process tomography quantum stochastic process synchronization unifilarity von Neumann entropy rate

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Area of Science:

Quantum Information Science
Quantum Thermodynamics
Stochastic Processes

Background:

Stationary quantum information sources generate sequences of correlated qudits, forming quantum stochastic processes.
Measurements on these qudit sequences by an observer yield classical stochastic processes.

Purpose of the Study:

To introduce quantum-information-theoretic properties for separable qudit sequences.
To establish bounds on the classical information properties of measured processes.
To develop methods for synchronizing with and reconstructing quantum information sources.

Main Methods:

Defining quantum-information-theoretic properties for separable qudit sequences.
Utilizing hidden Markov dynamics to describe observer synchronization.
Employing specific positive operator-valued measures and adaptive measurement protocols for synchronization.
Applying tomographic reconstruction for approximating information sources with classical models (i.i.d., Markov, etc.).

Main Results:

Introduced quantum-information-theoretic properties that bound classical information properties.
Demonstrated methods for observers to synchronize with the internal state of quantum sources.
Developed a tomographic reconstruction technique to approximate quantum sources with classical models.
Identified classes of separable processes based on quantum information properties and measurement complexity.

Conclusions:

Quantum information-theoretic properties provide a framework for understanding and bounding classical information derived from quantum sources.
Synchronization and reconstruction methods enable detailed analysis of quantum information sources, even those with hidden dynamics.
The study classifies quantum processes and highlights the role of measurement complexity in their analysis.