Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Calculation of Electric Flux

Calculation of Electric Flux

Consider the electric field of an oppositely charged, parallel-plate system and an imaginary box between those plates. Let the bottom face of the box be ABCD, and the top face be FGHK. The electric field between the plates is uniform and points from the positive plate toward the negative plate. The calculation of this field's flux through the box's various faces shows that the net flux through the box is zero. Why does the flux cancel out here?

Electric Flux

Electric Flux

The concept of flux describes how much of something goes through a given area. More formally, it is the dot product of a vector field within an area. For a better understanding, consider an open rectangular surface with a small area that is placed in a uniform electric field. The larger the area, the more field lines go through it and, hence, the greater the flux; similarly, the stronger the electric field (represented by a greater density of lines), the greater the flux. On the other hand, if...

Calculation of First-Law Quantities II

Calculation of First-Law Quantities II

The first law of thermodynamics establishes that the change in internal energy of a system is given by ΔU = q + w, where q is the heat exchanged, and w is the work performed. For a perfect gas, both internal energy (U) and enthalpy (H) depend solely on temperature. Consequently, for any change of state, whether reversible or irreversible, the internal energy change is determined by integrating the heat capacity at constant volume, and the enthalpy change by integrating the heat capacity at...

Magnetic Flux

Magnetic Flux

The magnetic flux measures the number of magnetic field lines passing through a given surface area. The SI unit for magnetic flux is the weber (Wb). Magnetic flux is a scalar quantity. It depends on three factors: the strength of the magnetic field B, the area through which the field lines pass, and the relative orientation of the field with the surface area.
Suppose a surface is divided into elements of area dA. For each element, the component of the magnetic field that is normal to the...

Calculation of First Law Quantities I

Calculation of First Law Quantities I

Thermodynamic systems undergoing phase transitions or temperature changes experience energy transfer in the form of heat (q) and work (w). For a reversible phase change at constant temperature (T) and pressure (p), the process involves no chemical reaction but results in energy exchange between distinct phases.The heat transferred during this process corresponds to the latent heat of transition, which is the amount of heat energy absorbed or released by a substance when it changes from one...

Fluorescence and Phosphorescence: Instrumentation

Fluorescence and Phosphorescence: Instrumentation

Fluorometers and spectrofluorometers are two types of instruments used for measuring molecular fluorescence. These instruments differ in how they select excitation and emission wavelengths and the type of light sources they utilize. Fluorometers use absorption interference filters to choose excitation and emission wavelengths. The excitation source in a fluorometer is typically a low-pressure mercury vapor lamp that emits intense lines distributed throughout the ultraviolet and visible regions.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Diffusion Coefficient of a Brownian Particle in Equilibrium and Nonequilibrium: Einstein Model and Beyond.

Entropy (Basel, Switzerland)·2023

Same author

Velocity Multistability vs. Ergodicity Breaking in a Biased Periodic Potential.

Entropy (Basel, Switzerland)·2022

Same author

Quasistatic work processes: When slowness implies certainty.

Physical review. E·2022

Same author

Improved bound on entropy production in a quantum annealer.

Physical review. E·2021

Same author

Charging a quantum battery via nonequilibrium heat current.

Physical review. E·2021

Same author

Comment on "Measurability of nonequilibrium thermodynamics in terms of the Hamiltonian of mean force".

Physical review. E·2021

Search research articles

Related Experiment Video

Updated: Jun 5, 2026

In Situ Measurement of Vacuum Window Birefringence using 25Mg+ Fluorescence

In Situ Measurement of Vacuum Window Birefringence using ²⁵Mg⁺ Fluorescence

Published on: June 13, 2020

Fluctuation theorems for continuously monitored quantum fluxes.

Michele Campisi¹, Peter Talkner, Peter Hänggi

¹Institute of Physics, University of Augsburg, Universitätsstrasse 1, D-86135 Augsburg, Germany.

Physical Review Letters

|January 15, 2011

Summary

Quantum fluctuation theorems are robust against measurements performed during force protocols. Probabilities change, but their ratio remains constant, enabling new experimental approaches.

More Related Videos

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts

Published on: December 1, 2018

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules

Published on: April 25, 2025

Related Experiment Videos

Last Updated: Jun 5, 2026

In Situ Measurement of Vacuum Window Birefringence using 25Mg+ Fluorescence

In Situ Measurement of Vacuum Window Birefringence using ²⁵Mg⁺ Fluorescence

Published on: June 13, 2020

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts

A Fluorescence Fluctuation Spectroscopy Assay of Protein-Protein Interactions at Cell-Cell Contacts

Published on: December 1, 2018

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules

Time-Resolved Fluorescence Anisotropy from Single Molecules for Characterizing Local Flexibility in Biomolecules

Published on: April 25, 2025

Area of Science:

Quantum physics
Statistical mechanics

Background:

Quantum fluctuation theorems are crucial for understanding non-equilibrium systems.
Current theories often rely on discrete measurements at the start and end of protocols.

Purpose of the Study:

To investigate the impact of intermediate measurements on quantum fluctuation theorems.
To reconcile theoretical predictions with experimental realities involving continuous monitoring.

Main Methods:

Theoretical analysis of quantum fluctuation theorems under measurement.
Examining how probabilities are altered by performing measurements during a force protocol.

Main Results:

Quantum fluctuation theorems are invariant to the number and type of observables measured during a protocol.
Intermediate measurements alter forward and backward probabilities but not their ratio.

Conclusions:

This invariance allows for the description of flux measurements.
Bridges the gap between discrete measurement theories and continuous monitoring experiments.