Related Experiment Video
Updated: Jun 5, 2026
09:06
Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
Quantum criticality without tuning in the mixed valence compound beta-YbAlB4
Yosuke Matsumoto1, Satoru Nakatsuji, Kentaro Kuga
1Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan.
Science (New York, N.Y.)
|January 22, 2011
Summary
This study reveals anomalous metallic behavior in β-YbAlB(4), showing quantum criticality without tuning. This challenges Fermi liquid theory in mixed-valence states, unlike magnetic Kondo systems.
Area of Science:
- Condensed Matter Physics
- Quantum Materials Science
Background:
- Fermi liquid theory describes conventional metals but faces challenges from anomalous metallic behavior near quantum phase transitions.
- Quantum phase transitions are often tuned by external parameters like magnetic fields or pressure, leading to a breakdown of Fermi liquid theory.
Purpose of the Study:
- To investigate the metallic behavior of the f-electron superconductor β-YbAlB(4) under high-precision measurements.
- To explore the possibility of quantum criticality occurring without external tuning in metallic systems.
Main Methods:
- High-precision magnetization measurements were performed on ultrapure β-YbAlB(4) samples.
- Analysis focused on the scaling of the free energy to identify signatures of quantum criticality.
Main Results:
- Magnetization measurements revealed free energy scaling indicative of zero-field quantum criticality.
- This critical behavior was observed in a mixed-valence state, not a magnetic Kondo lattice state.
Conclusions:
- The findings challenge the standard Fermi liquid theory in metals.
- β-YbAlB(4) exhibits a novel form of quantum criticality in a mixed-valence state, distinct from typical f-electron systems.
Related Concept Videos
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
02:45Valence Bond Theory
Overview of Valence Bond Theory
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
03:24Hybridization of Atomic Orbitals I
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
02:38Valence Bond Theory and Hybridized Orbitals
According to valence bond theory, a covalent bond results when: (1) an orbital on one atom overlaps an orbital on a second atom, and (2) the single electrons in each orbital combine to form an electron pair. The strength of a covalent bond depends on the extent of overlap of the orbitals involved. Maximum overlap is possible when the orbitals overlap on a direct line between the two nuclei.
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
02:32Bonding in Metals
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.