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

Imperfections in Crystal Structure: Stoichiometric Point Defects01:26

Imperfections in Crystal Structure: Stoichiometric Point Defects

Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...
Quantum Numbers02:43

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.
Electron Configurations02:46

Electron Configurations

Electron configurations and orbital diagrams can be determined by applying the Aufbau principle (each added electron occupies the subshell of lowest energy available), Pauli exclusion principle (no two electrons can have the same set of four quantum numbers), and Hund’s rule of maximum multiplicity (whenever possible, electrons retain unpaired spins in degenerate orbitals).
The relative energies of the subshells determine the order in which atomic orbitals are filled (1s, 2s, 2p, 3s, 3p, 4s,...
¹H NMR: Interpreting Distorted and Overlapping Signals01:02

¹H NMR: Interpreting Distorted and Overlapping Signals

Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
Ionic Crystal Structures02:42

Ionic Crystal Structures

Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Molecular Orbital Theory II03:51

Molecular Orbital Theory II

Molecular Orbital Energy Diagrams

You might also read

Related Articles

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

Sort by
Same author

Classification and correlation signatures of chiral spin liquids on the pyrochlore lattice.

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

Topochemical Fluorination Yields Long-Range Superlattice in Epitaxial La<sub>2</sub>NiO<sub>4</sub> Thin Films.

ACS nano·2026
Same author

Thermoelectric Detection of Crossed Andreev Reflections in Quantum Hall/Superconductor Hybrid Structures.

Nature communications·2026
Same author

Room-temperature multistage metastability in a moiré superstructure.

Nature communications·2026
Same author

Identifying Instabilities with Quantum Geometry in Flat-Band Systems.

Physical review letters·2026
Same author

Topological Chiral Superconductivity in the Triangular-Lattice Hofstadter-Hubbard Model.

Physical review letters·2026
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 16, 2026

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
05:39

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Published on: August 2, 2019

Order by quantum disorder in Er2Ti2O7.

Lucile Savary1, Kate A Ross, Bruce D Gaulin

  • 1Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.

Physical Review Letters
|December 11, 2012
PubMed
Summary
This summary is machine-generated.

Researchers found a unique U(1) degeneracy in Er(2)Ti(2)O(7) materials. Quantum fluctuations break this symmetry, confirming the "order by disorder" phenomenon with experimental evidence.

More Related Videos

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
14:58

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

Published on: June 3, 2015

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides
09:41

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides

Published on: May 29, 2018

Related Experiment Videos

Last Updated: May 16, 2026

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
05:39

Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform

Published on: August 2, 2019

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
14:58

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

Published on: June 3, 2015

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides
09:41

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides

Published on: May 29, 2018

Area of Science:

  • Condensed matter physics
  • Quantum magnetism
  • Frustrated magnetic systems

Background:

  • Pyrochlore materials exhibit complex magnetic behavior due to their unique lattice structure.
  • Understanding spin Hamiltonians and their degeneracies is crucial for developing new magnetic materials.
  • The U(1) degeneracy in spin systems is a theoretical concept with limited experimental confirmation.

Purpose of the Study:

  • To establish the systematic existence of U(1) degeneracy in symmetry-allowed Hamiltonians on the pyrochlore lattice.
  • To investigate the role of this degeneracy in the classical ground states of Er(2)Ti(2)O(7).
  • To demonstrate how quantum fluctuations break this degeneracy and confirm theoretical predictions with experimental data.

Main Methods:

  • Mean-field theory to establish U(1) degeneracy.
  • Inelastic neutron scattering to extract the Hamiltonian of Er(2)Ti(2)O(7).
  • Experimental verification of theoretical predictions regarding symmetry breaking and order by disorder.

Main Results:

  • Systematic existence of U(1) degeneracy for all symmetry-allowed Hamiltonians quadratic in spins on the pyrochlore lattice at the mean-field level.
  • The U(1)-degenerate states are the classical ground states of Er(2)Ti(2)O(7).
  • Quantum fluctuations were shown to break this degeneracy in a manner consistent with experimental observations.

Conclusions:

  • The study provides unprecedented symmetry protection for classical U(1) degeneracy in Er(2)Ti(2)O(7).
  • The observation of "order by disorder" is definitively confirmed in this material.
  • The findings offer verifiable consequences and comparisons between theory and experiment for frustrated magnetic systems.