Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Charging Conductors By Induction01:15

Charging Conductors By Induction

8.3K
The Earth is a good conductor of electricity, and it is so big that it can be considered an infinite source or sink of charges. It can easily exchange charges with any matter.
Generally, conductors like metals do not allow any excess charge to be present on them. Any excess charge added to metals easily flows away, for example, when a metal is placed on the Earth. This process is called earthing.
However, conductors can be charged by a process called induction. For example, consider charging a...
8.3K
Efficiency of The Carnot Cycle01:16

Efficiency of The Carnot Cycle

2.9K
The hypothetical Carnot cycle consists of an ideal gas subjected to two isothermal and two adiabatic processes. Since the internal energy of an ideal gas depends only on its temperature, which is the same before and after the completion of the Carnot cycle, there is no change in its internal energy. Hence, using the first law of thermodynamics, the total heat exchanged by the ideal gas equals the total work done. Thus, we can quantify the efficiency of the Carnot cycle via the heat exchanged...
2.9K
Torque On A Current Loop In A Magnetic Field01:13

Torque On A Current Loop In A Magnetic Field

4.8K
The most common application of magnetic force on current-carrying wires is in electric motors. These consist of loops of wire, which are placed between the magnets with a magnetic field. When current flows through the loops, the magnetic field applies torque, which causes the shaft to rotate, thus converting electrical energy to mechanical energy.
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
4.8K
The Hall Effect01:30

The Hall Effect

2.8K
Edwin H. Hall, in the year 1879, devised an experiment that could be used to identify the polarity of the predominant charge carriers in a conducting material. From a historical perspective, this experiment was the first to demonstrate that the charge carriers in most metals are negative.
2.8K
Charge on a Conductor01:26

Charge on a Conductor

4.8K
An interesting property of a conductor in static equilibrium is that extra charges on the conductor end up on its outer surface, regardless of where they originate. Consider a hollow metallic conductor with a uniform surface charge density. Since the conductor itself is in electrostatic equilibrium, there should not be any electric field inside the conductor. Now, assume a Gaussian surface enclosing the hollow portion. Applying Gauss's law, the inner surface of the hollow conductor will not...
4.8K
The Carnot Cycle and the Second Law of Thermodynamics01:20

The Carnot Cycle and the Second Law of Thermodynamics

2.9K
The Carnot engine works between two heat reservoirs of fixed temperatures. The Carnot cycle begs the following question: Is it possible to devise a heat engine that is more efficient than a Carnot engine between two fixed temperatures? The answer lies in designing a Carnot refrigerator.
Since the individual steps in a Carnot cycle can be reversed, the entire cycle is, thus, reversible. If a Carnot cycle is reversed, it becomes a Carnot refrigerator. It extracts heat Qc from a cold reservoir at...
2.9K

You might also read

Related Articles

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

Sort by
Same author

Information-theoretic analysis of temporal dependence in discrete stochastic processes: Application to precipitation predictability.

Chaos (Woodbury, N.Y.)·2026
Same author

Entropy Estimators for Markovian Sequences: A Comparative Analysis.

Entropy (Basel, Switzerland)·2024
Same author

Modeling language ideologies for the dynamics of languages in contact.

Chaos (Woodbury, N.Y.)·2023
Same author

Electrostatic Tuning of Bilayer Graphene Edge Modes.

Nanomaterials (Basel, Switzerland)·2023
Same author

Time-resolved Coulomb collision of single electrons.

Nature nanotechnology·2023
Same author

Ordinal analysis of lexical patterns.

Chaos (Woodbury, N.Y.)·2023
Same journal

Demonstration of a quantum C-NOT gate in a time-multiplexed fully reconfigurable photonic processor.

Nature communications·2026
Same journal

Nonlinear quantum light source with van der Waals ferroelectric NbOX<sub>2</sub> (X = Br, I).

Nature communications·2026
Same journal

Antagonistic histone H2A variants and autonomous heterochromatin formation shape epigenomic patterns in Arabidopsis.

Nature communications·2026
Same journal

The long tail of nitrate pollution in groundwater challenges governance of global water quality.

Nature communications·2026
Same journal

Select microbial metabolites promote tau aggregation in a murine tauopathy model.

Nature communications·2026
Same journal

Warming climate has lengthened global intense tropical cyclone seasons.

Nature communications·2026
See all related articles

Related Experiment Video

Updated: Sep 24, 2025

Fabrication and Operation of a Nano-Optical Conveyor Belt
11:10

Fabrication and Operation of a Nano-Optical Conveyor Belt

Published on: August 26, 2015

11.7K

Beating Carnot efficiency with periodically driven chiral conductors.

Sungguen Ryu1, Rosa López2, Llorenç Serra2

  • 1Instituto de Física Interdisciplinar y Sistemas Complejos IFISC (CSIC-UIB), E-07122, Palma, Spain. sungguen@ifisc.uib-csic.es.

Nature Communications
|May 6, 2022
PubMed
Summary
This summary is machine-generated.

Quantum microengines can surpass the Carnot limit, defying classical thermodynamics. This research shows a quantum chiral conductor can achieve higher efficiencies by using AC voltage, preserving the second law of thermodynamics.

More Related Videos

Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
11:21

Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving

Published on: March 30, 2017

7.6K
Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers
12:37

Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers

Published on: September 4, 2015

12.5K

Related Experiment Videos

Last Updated: Sep 24, 2025

Fabrication and Operation of a Nano-Optical Conveyor Belt
11:10

Fabrication and Operation of a Nano-Optical Conveyor Belt

Published on: August 26, 2015

11.7K
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
11:21

Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving

Published on: March 30, 2017

7.6K
Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers
12:37

Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers

Published on: September 4, 2015

12.5K

Area of Science:

  • Quantum thermodynamics
  • Mesoscopic physics
  • Condensed matter physics

Background:

  • Classical thermodynamics dictates that ideal thermal machines are bound by the Carnot efficiency limit.
  • The validity of this limit for microengines operating far from thermodynamic equilibrium remains an open question.
  • Recent advancements focus on small conductors to explore the fundamental limits of thermodynamic engines.

Purpose of the Study:

  • To investigate whether microengines operating far from equilibrium can exceed the Carnot efficiency limit.
  • To analyze the thermodynamic performance of a quantum chiral conductor driven by AC voltage.
  • To determine if the second law of thermodynamics is preserved under these conditions.

Main Methods:

  • Theoretical analysis of a quantum chiral conductor subjected to an AC voltage.
  • Investigation of photoassisted excitation processes and their role in entropy production.
  • Examination of work extraction from temperature baths and its implications for thermodynamic laws.

Main Results:

  • Demonstration that a quantum chiral conductor can achieve efficiencies significantly exceeding the Carnot bound.
  • Observation of work extraction from temperature baths, seemingly violating the Kelvin-Planck statement.
  • Confirmation that entropy production remains positive, preserving the second law of thermodynamics with a proper definition.

Conclusions:

  • The study highlights that efficiencies beyond the Carnot limit are achievable in specific quantum systems.
  • Key factors enabling超-Carnot efficiencies include irreversible entropy production via AC field-induced excitations and chirality-induced absence of power injection.
  • These findings offer crucial insights into the fundamental limits of thermodynamic engines at the microscale.