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

The Quantum-Mechanical Model of an Atom

The Quantum-Mechanical Model of an Atom

Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.

Entropy and the Second Law of Thermodynamics

Entropy and the Second Law of Thermodynamics

The second law of thermodynamics can be stated quantitatively using the concept of entropy. Entropy is the measure of disorder of the system.
The relation between entropy and disorder can be illustrated with the example of the phase change of ice to water. In ice, the molecules are located at specific sites giving a solid state, whereas, in a liquid form, these molecules are much freer to move. The molecular arrangement has therefore become more randomized. Although the change in average...

Entropy Change in Reversible Processes

Entropy Change in Reversible Processes

In the Carnot engine, which achieves the maximum efficiency between two reservoirs of fixed temperatures, the total change in entropy is zero. The observation can be generalized by considering any reversible cyclic process consisting of many Carnot cycles. Thus, it can be stated that the total entropy change of any ideal reversible cycle is zero.
The statement can be further generalized to prove that entropy is a state function. Take a cyclic process between any two points on a p-V diagram.

Entropy

Entropy

The first law of thermodynamics is quantitatively formulated via an equation relating the internal energy of a system, the heat exchanged by it, and the work done on it. A quantitative formulation of the second law of thermodynamics leads to defining a state function, the entropy.
When an ideal gas expands isothermally, the disorder in the gas increases. From the molecular perspective, the gas molecules have more volume to move around in.
Consider an infinitesimal step in the expansion, which...

Standard Entropy Change for a Reaction

Standard Entropy Change for a Reaction

Entropy is a state function, so the standard entropy change for a chemical reaction (ΔS°rxn) can be calculated from the difference in standard entropy between the products and the reactants.

The Uncertainty Principle

The Uncertainty Principle

Werner Heisenberg considered the limits of how accurately one can measure properties of an electron or other microscopic particles. He determined that there is a fundamental limit to how accurately one can measure both a particle’s position and its momentum simultaneously. The more accurate the measurement of the momentum of a particle is known, the less accurate the position at that time is known and vice versa. This is what is now called the Heisenberg uncertainty principle. He...

You might also read

Related Articles

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

Sort by

Same author

TEAD inhibitor induced switch in energy metabolism drives human podocyte injury in vitro.

Archives of toxicology·2026

Same author

Colonic Continuity After Splenic Flexure Resection: Does the Orientation of the Anastomosis Matter? A Retrospective Cohort Study.

Annali italiani di chirurgia·2026

Same author

TRPML1 agonists synergize with enzyme replacement therapy in fibroblasts from Pompe disease patients.

Journal of translational medicine·2026

Same author

Autonomous quantum processing unit: an autonomous thermal computing machine & its physical limitations.

Reports on progress in physics. Physical Society (Great Britain)·2026

Same author

HKDC1 contributes to aberrant lysosome-mitochondria contact in Niemann-Pick disease type C.

bioRxiv : the preprint server for biology·2026

Same author

Ninth BHD International Symposium: Advancing research through global collaboration.

Cell stress & chaperones·2026

Search research articles

Related Experiment Video

Updated: Jan 9, 2026

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

Entropic Costs of Extracting Classical Ticks from a Quantum Clock.

Vivek Wadhia¹, Florian Meier², Federico Fedele¹

¹University of Oxford, Department of Engineering Science, Parks Road, Oxford OX1 3PJ, United Kingdom.

Physical Review Letters

|November 30, 2025

Summary

We built a quantum clock using charge tunneling in a double quantum dot (DQD). Measuring the entropy of the readout amplified precision, revealing the true thermodynamic cost of quantum timekeeping.

More Related Videos

Gradient Echo Quantum Memory in Warm Atomic Vapor

Gradient Echo Quantum Memory in Warm Atomic Vapor

Published on: November 11, 2013

Large Scale Energy Efficient Sensor Network Routing Using a Quantum Processor Unit

Large Scale Energy Efficient Sensor Network Routing Using a Quantum Processor Unit

Published on: September 8, 2023

Related Experiment Videos

Last Updated: Jan 9, 2026

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

Gradient Echo Quantum Memory in Warm Atomic Vapor

Gradient Echo Quantum Memory in Warm Atomic Vapor

Published on: November 11, 2013

Large Scale Energy Efficient Sensor Network Routing Using a Quantum Processor Unit

Large Scale Energy Efficient Sensor Network Routing Using a Quantum Processor Unit

Published on: September 8, 2023

Area of Science:

Quantum physics
Thermodynamics
Quantum information science

Background:

Quantum clocks offer high precision timekeeping.
Understanding the thermodynamic costs of quantum systems is crucial.

Purpose of the Study:

To experimentally realize a quantum clock using charge tunneling.
To investigate the thermodynamic cost of microscopic tick generation and macroscopic recording.
To explore the interplay between quantum clockwork entropy and measurement apparatus.

Main Methods:

Utilized a charge sensor to count tunneling events in a double quantum dot (DQD) as clock ticks.
Measured power dissipation of the DQD and charge sensor in DC and RF modes.
Analyzed the thermodynamic cost of both microscopic tick creation and macroscopic recording.

Main Results:

Demonstrated that the measurement apparatus's entropy production significantly exceeds the clockwork's.
Showcased that enhanced precision is achieved by exploiting the measurement record, even at equilibrium.
Identified measurement-related entropy as the dominant thermodynamic cost in quantum timekeeping.

Conclusions:

The entropy produced by amplification and measurement is the fundamental thermodynamic cost of quantum timekeeping.
Macroscopic measurement significantly impacts and improves quantum clock precision.
This work provides a microscopic understanding of the thermodynamic limits of timekeeping.