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Related Experiment Video

Updated: May 10, 2025

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

Published on: May 30, 2014

On Dynamical Measures of Quantum Information.

James Fullwood¹, Arthur J Parzygnat²

¹School of Mathematics Statistics, Hainan University, 58 Renmin Avenue, Haikou 570228, China.

Entropy (Basel, Switzerland)

|April 26, 2025

Summary

This study introduces a new joint entropy for quantum systems evolving over time, generalizing von Neumann entropy to spacetime. This framework quantifies information dynamics and conservation in quantum processes.

Keywords:

entropy mutual information quantum information

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Last Updated: May 10, 2025

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Area of Science:

Quantum Information Theory
Quantum Thermodynamics
Spacetime Physics

Background:

The standard von Neumann entropy applies to static quantum states.
Extending entropy measures to time-dependent quantum systems is crucial for understanding quantum dynamics.

Purpose of the Study:

To define joint entropy for timelike-separated quantum systems.
To develop a spacetime generalization of von Neumann entropy.
To formulate dynamical extensions of quantum information measures.

Main Methods:

Utilizing the theory of quantum states evolving over time.
Defining joint entropy for timelike-separated systems with dual spacelike descriptions.
Developing dynamical extensions for quantum joint entropy, conditional entropy, and mutual information.

Main Results:

A novel joint entropy for timelike-separated quantum systems is established.
This entropy generalizes von Neumann entropy and quantifies information dynamics.
Information conservation in quantum processes is precisely formulated.

Conclusions:

The proposed dynamical entropy offers a spacetime generalization of quantum information measures.
It provides a framework for understanding information loss/gain during quantum evolution.
The entropy has an operational interpretation in terms of state disturbance during measurements.