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

Entropy and the Second Law of Thermodynamics01:26

Entropy and the Second Law of Thermodynamics

Consider an isolated system in which a hot object is placed in contact with a cold one. This is an irreversible process that eventually leads both objects to reach the same equilibrium temperature. It is crucial to note that the constituents of any substance exhibit increased disorder at higher temperatures. As a cold substance absorbs heat, its constituents become more disordered. The energy transfer from a hotter object to a cooler one increases the system's disorder or randomness. This...
Entropy and the Second Law of Thermodynamics01:20

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...
The Second Law of Thermodynamics01:14

The Second Law of Thermodynamics

In the quest to identify a property that may reliably predict the spontaneity of a process, a promising candidate has been identified: entropy. Scientists refer to the measure of randomness or disorder within a system as entropy. High entropy means high disorder and low energy. To better understand entropy, think of a student’s bedroom. If no energy or work were put into it, the room would quickly become messy. It would exist in a very disordered state, one of high entropy. Energy must be put...
Entropy02:39

Entropy

Salt particles that have dissolved in water never spontaneously come back together in solution to reform solid particles. Moreover, a gas that has expanded in a vacuum remains dispersed and never spontaneously reassembles. The unidirectional nature of these phenomena is the result of a thermodynamic state function called entropy (S). Entropy is the measure of the extent to which the energy is dispersed throughout a system, or in other words, it is proportional to the degree of disorder of a...
Entropy01:18

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...
Second Law of Thermodynamics02:49

Second Law of Thermodynamics

In the quest to identify a property that may reliably predict the spontaneity of a process, a promising candidate has been identified: entropy. Processes that involve an increase in entropy of the system (ΔS > 0) are very often spontaneous; however, examples to the contrary are plentiful. By expanding consideration of entropy changes to include the surroundings, a significant conclusion regarding the relation between this property and spontaneity may be reached. In thermodynamic models, the...

You might also read

Related Articles

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

Sort by
Same author

All pure multipartite entangled states of qubits can be self-tested.

Nature communications·2026
Same author

Mapping Phase Diagrams of Quantum Spin Systems through Semidefinite-Programming Relaxations.

Physical review letters·2026
Same author

Equilibrium propagation for learning in Lagrangian dynamical systems.

Physical review. E·2025
Same author

Prepare-and-Measure Scenarios with Photon-Number Constraints.

Physical review letters·2025
Same author

Weak Kerr nonlinearity boosts the performance of frequency-multiplexed photonic extreme learning machines: a multifaceted approach.

Optics express·2025
Same author

Efficient optimisation of physical reservoir computers using only a delayed input.

Communications engineering·2025
Same journal

Erratum: Bacterial Turbulence at Compressible Fluid Interfaces [Phys. Rev. Lett. 136, 138301 (2026)].

Physical review letters·2026
Same journal

Unveiling Light-Quark Yukawa Flavor Structure via Dihadron Fragmentation at Lepton Colliders.

Physical review letters·2026
Same journal

Adaptable Route to Fast Coherent State Transport via Bang-Bang-Bang Protocols.

Physical review letters·2026
Same journal

Topological Transition and Emergence of Elasticity of Dislocation in Skyrmion Lattice: Beyond Kittel's Magnetic-Polar Analogy.

Physical review letters·2026
Same journal

Pound-Drever-Hall Method for Superconducting-Qubit Readout.

Physical review letters·2026
Same journal

Coupling a ^{73}Ge Nuclear Spin to an Electrostatically Defined Quantum Dot in Silicon.

Physical review letters·2026
See all related articles

Related Experiment Video

Updated: May 23, 2026

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
07:56

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference

Published on: September 5, 2019

Randomness versus nonlocality and entanglement.

Antonio Acín1, Serge Massar, Stefano Pironio

  • 1ICFO-Institut de Ciencies Fotoniques, Avenida Carl Friedrich Gauss 3, 08860 Castelldefels (Barcelona), Spain.

Physical Review Letters
|April 3, 2012
PubMed
Summary
This summary is machine-generated.

Quantum correlations can generate close to 2 bits of randomness, even with minimal nonlocality or entanglement. This finding demonstrates that nonlocality, entanglement, and randomness are distinct, enabling optimal device-independent quantum key distribution and randomness generation.

More Related Videos

Fabrication and Characterization of Disordered Polymer Optical Fibers for Transverse Anderson Localization of Light
09:19

Fabrication and Characterization of Disordered Polymer Optical Fibers for Transverse Anderson Localization of Light

Published on: July 29, 2013

Related Experiment Videos

Last Updated: May 23, 2026

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
07:56

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference

Published on: September 5, 2019

Fabrication and Characterization of Disordered Polymer Optical Fibers for Transverse Anderson Localization of Light
09:19

Fabrication and Characterization of Disordered Polymer Optical Fibers for Transverse Anderson Localization of Light

Published on: July 29, 2013

Area of Science:

  • Quantum Information Science
  • Foundations of Quantum Mechanics
  • Quantum Cryptography

Background:

  • Bell tests with two-outcome measurements can theoretically yield up to 2 bits of randomness.
  • Maximal violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality only guarantees 1.23 bits of randomness.

Purpose of the Study:

  • To demonstrate that near-maximal randomness generation is achievable with minimal nonlocality and entanglement.
  • To establish the inequivalence of nonlocality, entanglement, and randomness.
  • To explore implications for device-independent quantum technologies.

Main Methods:

  • Theoretical analysis of quantum correlations in Bell tests.
  • Investigation of randomness certification with varying degrees of nonlocality and entanglement.

Main Results:

  • Quantum correlations with arbitrarily low nonlocality can certify near-maximal randomness generation (close to 2 bits).
  • Quantum states with arbitrarily low entanglement can also certify near-maximal randomness.
  • Nonlocality, entanglement, and randomness are shown to be inequivalent quantities.

Conclusions:

  • Device-independent quantum key distribution can achieve optimal rates using almost-local correlations.
  • Device-independent randomness generation can achieve optimal rates with almost-local correlations and almost-unentangled states.