Related Experiment Video
Updated: Jul 4, 2025
09:06
Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.1K
Spin-Triplet Superconductivity from Quantum-Geometry-Induced Ferromagnetic Fluctuation
Taisei Kitamura1, Akito Daido1, Youichi Yanase1
1Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Physical Review Letters
|February 2, 2024
Summary
Quantum geometry drives ferromagnetic fluctuations, leading to spin-triplet superconductivity. This occurs particularly with non-Kramers band degeneracy, where quantum metrics favor such fluctuations.
Area of Science:
- Condensed matter physics
- Quantum materials
Background:
- Superconductivity is a quantum mechanical phenomenon where a material can conduct electricity with zero resistance.
- Spin-triplet superconductivity is a less common form with unique properties.
- Understanding the mechanisms driving different types of superconductivity is crucial for materials science.
Purpose of the Study:
- To investigate the role of quantum geometry in inducing ferromagnetic fluctuations.
- To establish the link between quantum geometry, ferromagnetic fluctuations, and spin-triplet superconductivity.
- To clarify the criteria for ferromagnetic fluctuation in novel superconducting materials.
Main Methods:
- Analysis of effective mass and quantum geometry contributions to ferromagnetic fluctuation.
- Utilizing the Fubini-Study quantum metric to assess its influence on ferromagnetic fluctuation.
- Solving the linearized gap equation using random phase approximation for effective interactions.
Main Results:
- Quantum geometry was shown to induce ferromagnetic fluctuations.
- The Fubini-Study quantum metric significantly favors ferromagnetic fluctuation in the presence of non-Kramers band degeneracy near the Fermi surface.
- Spin-triplet superconductivity is mediated by these quantum-geometry-induced ferromagnetic fluctuations.
Conclusions:
- Quantum geometry is a key factor in realizing spin-triplet superconductivity.
- The findings provide a new pathway for designing materials with specific superconducting properties.
- This work deepens the understanding of the interplay between topology and electronic correlations in superconductors.
Related Concept Videos
01:31Ferromagnetism
2.4K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.4K
01:03Atomic Nuclei: Nuclear Spin State Overview
952
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of...
952
01:08Spin–Spin Coupling Constant: Overview
924
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
924
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
1.1K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
1.1K
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
981
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
981
01:23Atomic Nuclei: Nuclear Relaxation Processes
654
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
654