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

Quantum Numbers

Quantum Numbers

It is said that the energy of an electron in an atom is quantized; that is, it can be equal only to certain specific values and can jump from one energy level to another but not transition smoothly or stay between these levels.

Dual Nature of Electromagnetic (EM) Radiation

Dual Nature of Electromagnetic (EM) Radiation

Electromagnetic (EM) radiation consists of electric and magnetic field components oscillating in planes perpendicular to each other and mutually perpendicular to radiation propagation through space. EM radiation can be classified as a wave, characterized by the properties of waves such as wavelength (denoted as λ) and frequency (represented by ν).
Wavelength is the distance between two consecutive peaks (the highest point) or troughs (the lowest point) in the wave. Frequency is the number of...

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. Schrödinger...

The Pauli Exclusion Principle

The Pauli Exclusion Principle

The arrangement of electrons in the orbitals of an atom is called its electron configuration. We describe an electron configuration with a symbol that contains three pieces of information:

Limits to Natural Selection

Limits to Natural Selection

Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.

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.

You might also read

Related Articles

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

Sort by

Same author

Shake before Use: Universal Enhancement of Quantum Thermometry by Unitary Driving.

Physical review letters·2026

Same author

Qualitative and quantitative hard-tissue MRI with portable Halbach scanners.

Scientific reports·2026

Same author

Experimental memory control in continuous-variable optical quantum reservoir computing.

Nature photonics·2026

Same author

Optimal quantum transport on a ring via locally monitored chiral quantum walks.

Physical review. E·2025

Same author

Enhanced Quantum Frequency Estimation by Nonlinear Scrambling.

Physical review letters·2025

Same author

Privacy in Networks of Quantum Sensors.

Physical review letters·2025

Search research articles

Related Experiment Video

Updated: May 14, 2026

Gradient Echo Quantum Memory in Warm Atomic Vapor

Gradient Echo Quantum Memory in Warm Atomic Vapor

Published on: November 11, 2013

Discording power of quantum evolutions.

Fernando Galve¹, Francesco Plastina, Matteo G A Paris

¹IFISC, UIB-CSIC, Instituto de Física Interdisciplinar y Sistemas Complejos, UIB Campus, E-07122 Palma de Mallorca, Spain.

Physical Review Letters

|February 7, 2013

Summary

We introduce discording power to measure how well quantum gates create quantum discord. Certain gates, like sqrt[SWAP], perfectly generate discord for all purity levels, unlike CNOT gates.

More Related Videos

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: May 14, 2026

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 Information Science
Quantum Computing

Background:

Quantum discord quantifies non-classical correlations beyond entanglement.
Understanding the creation of quantum discord by quantum gates is crucial for quantum information processing.

Purpose of the Study:

Introduce and analyze the 'discording power' of unitary transformations.
Assess the capability of two-qubit gates to generate quantum discord.
Generalize entanglement measures to arbitrary purity values.

Main Methods:

Utilize the Cartan decomposition of two-qubit unitaries.
Evaluate maximum achievable discord on classical-classical states at fixed purity.
Analyze specific two-qubit gates, including CNOT and sqrt[SWAP].

Main Results:

Identify 'perfect discorders'—gates that generate maximum discord across all purity levels.
Demonstrate that sqrt[SWAP] and related gates are perfect discorders.
Show that CNOT gates are perfect discorders only for low or unit purity, not intermediate values.
Establish discording power as a generalization of entanglement measures.

Conclusions:

Discording power provides a robust measure for quantifying discord generation by quantum gates.
Gate-dependent properties significantly influence their ability to create quantum discord.
The findings offer insights into designing quantum gates for specific quantum information tasks.